request for proposal (rfp) fabrication of ......sac-isro page 2 of 45 specifications for fabrication...

REQUEST FOR PROPOSAL (RFP)

FABRICATION OF ORIGAMI LENS FOR

BANDS B1-B4

March 2019

SPACE APPLICATIONS CENTRE

INDIAN SPACE RESEARCH ORGANIZATION (ISRO)

AHMEDABAD – 380015

SAC-ISRO Page 1 of 45

Specifications for fabrication and testing of Origami Lens

The optical design of the multi-fold lenses presented in this RFP is the proprietary work of Space Applications Center (ISRO) and shall not be used for any other

purpose except for preparation of the offer for fabrication.

CONTENTS Section I Introduction 2

Section II Optical/mechanical/thermal requirements 5

Section III Specifications of front and rear surfaces of Origami lens 8

Section IV Final specifications of Origami lens 10

Section V Quality provisions 12

Section VI Test requirements 15

Section VII Documents required 18

Section VIII Deliverables and packaging 19

ANNEXUREs

ANNEXURE 1 Design / Sag Specifications 21

ANNEXURE 2 Coating / Black Paint On Lens - Specifications 25

ANNEXURE 3 Tolerance Specifications 35

ANNEXURE 4 References 36

ANNEXURE 5 Compliance Matrix for RFP 37

ANNEXURE 5 Mechanical Drawings 41





SECTION I

INTRODUCTION

1.1 Scope

After successful implementation of proof-of-concept models of 8-fold and 4-fold

origami lens, we extend the scope of the Origami lens activity for development of a 4-

band camera with IRS bands B1-B4. In this document, the procurement specifications

for fabrication and testing of four-fold Origami Lens for development of compact

camera system are given. This document specifies the details necessary for the design

and testing of the compact lenses.

The scope of the work includes:

Study of the specifications provided by SAC.

Procurement of the blanks required for fabricating Origami lenses.

Fabrication of four-fold lenses as per the specifications given in this document

Meeting the performance parameters as per the specifications / standards

Demonstration of the performance of the lenses as per the specifications.

Provide test data to SAC for dispatch clearance.

Packaging in a suitable container and shipment to SAC.

This document covers:

- A general description of Origami Lens - Optical specifications of the lens - Tolerance specifications - Required optical testing for quality assurance - Deliverables - Schedule

1.2 General description of Origami Lenses Taking advantage of both reflective and refractive optical systems, light is folded

multiple times in a single crystal for designing the camera optics with desired

performance. Light enters through an annular aperture and with the help of concentric

zone reflectors, it is focused at the image plane. Folding the light helps to achieve the

desired focal length without increasing the total optical track. To achieve desired

performance, aspheric surfaces are used which also help to minimize aberrations and

improve the design tolerances with increase in depth of focus of an optical system. With

folded optics, the region between reflectors can be cut into baffles and made absorbing

to reduce stray light effects.





The origami lens based camera system would be used for airborne applications.

A solid CaF2 geometry has been chosen to increase the achievable FOV, which is

limited by the reflective geometry. In contrast to the eight-reflection lens, the front and

back sides of the four-reflection lens are designed aspheric.

The lens is designed with 4-fold bi-aspheric surfaces having 67.5 mm focal length with

an overall clear aperture diameter of 65 mm and physical diameter of 70mm. This

obscured system has an effective aperture of 36.55mm and f-number of 1.85 which

covers ±6.8 degree field of view. Figure 1 shows a typical optical schematic of the lens.

Figure 1: Typical 2-D Optical Schematic of 4-fold lens

Detailed description for the development of the four-fold origami is given in the

following sections.

1.3 Applicable Documents

The latest revision of the following documents (including but not limited to) form a part

of specifications.

MIL-0-13830C - Optical components for fire control instruments: General

specification covering the manufacture, assembly and

inspection of

MIL-M-13508C - Mirrors, glass, front surfaces aluminized for optical

elements

MIL-0-16898 - Optical elements packaging





MIL-675C - Coating of glass elements (Anti-Reflection) MIL-C-48497 - Durability requirement for coating single or multilayer,

interference …

MIL-I-45208 - Inspection requirements

1.4 Test Sequence

The test sequence as given in this document shall be adhered to. No other additions,

deletions and/or alterations to the test sequence and/or test specifications shall be done

without formal approval from SAC (ISRO).

1.5 Conditions and methods of test

The test conditions shall be in accordance with the specifications given in this

document. The test methods and the measurement procedures shall be worked out by

the supplier and submitted to SAC (ISRO) for approval. In any case, the supplier has

no right to implement any changes in the conditions or methods of the test without

formal approval from SAC (ISRO).

1.6 Supplier’s responsibility

The supplier shall be responsible for fabrication and testing of the 4-fold lens as per the

relevant specifications within the performance limits in the scheduled timeline. The

supplier shall also be responsible for delivering the product safely to the SAC. Any

lapse on the part of this would be the responsibility of the supplier.

1.7 Inspection rights

SAC reserves the right to participate in and monitor any of the tests and inspections

called for in this document. The supplier shall submit a schedule of activities, including

major milestones to SAC.





SECTION II

OPTICAL/MECHANICAL/THERMAL REQUIREMENTS

Total 04 Origami lenses are to be fabricated by the vendor. Thereafter, based on SAC’s

feedback of coating qualification, supplier has to take up coating of lenses.

2.1 The following are the optical, mechanical and thermal requirements to be met

for realization of the multi-fold Origami lens.

High quality CaF2 glass with high material homogeneity shall be used for fabrication of Origami lenses. The physical/ mechanical/ thermal properties of

the material batch to be used shall be sent to SAC.

Proper stress relieving shall be carried out on the blanks. This is to ensure that there is no stress on the Origami lens during diamond turning and testing.

The manufacturer shall ensure that holding of the components does not induce any stresses and result in surface figure changes on removal of the component

from the fabrication/test fixtures. The manufacturer shall device suitable test

methods to demonstrate this aspect.

2.2 Scope of Work

Fabrication and testing of origami optics involves -

1. Study of optical design provided by SAC

2. Design of reflective coatings and providing response curves to SAC

3. Qualification of coating by vendor as per details specified in RFP

4. Fabrication of Origami lenses

5. Coating of lens elements as per SAC feedback

6. Black painting of optics as per the details specified in RFP

7. Testing to ensure compliance to the specifications provided

8. Preparing test reports and providing to SAC for review and approval

9. Dispatch of optics to SAC

Fabrication and testing should be carried out to the best of engineering practices.

2.3 Sequence of Activities

1. The supplier shall study the optical design provided by SAC. Supplier shall prepare

the work plan for fabrication, coating and testing of the optics. The work plan shall

be submitted to SAC for approval.

2. SAC shall have the right to carry out minor modifications in the optical design

before the fabrication starts at no extra cost.





3. Procurement of all optical glasses, thermal paint etc. shall be initiated immediately

on receipt of purchase order.

4. The melt values of procured CaF2 glass shall be provided to SAC as soon as they

become available to adjust melt values in the optical design.

All materials shall be procured in ONE lot and from the same batch.

5. Response plots (in excel sheet) for coating design is to be provided to SAC for

approval.

6. Coating trial runs to be made and testing to be carried out to ensure compliance to

appropriate MIL standards. Results of the coating runs to be provided to SAC along

with the coating witness samples.

7. Fabrication of optical components including black painting as required.

8. Dimensions of all fabricated parts to be provided to SAC for approval. All

dimensions should be measured very accurately, preferably, in 3D CMM.

9. Measured data (Radius of curvature, SAG) of individual zones to be provided to

SAC for approval.

10. Optical testing to be carried out by vendor as per details provided in RFP (sections

IV & VI)

11. Review of all measured data by SAC and compliance to the specifications.

12. Prepare proper packaging before dispatching the optics to SAC in suitable

containers.

2.4 Anti-reflection coating on the optical surfaces

The fabricator is responsible for the design and qualification of antireflection coatings

as per the relevant MIL / ISO standards. After qualification to MIL standards,

deposition of Anti-reflection coatings on optical surfaces (specified zones) is to be

carried out (refer Annexure 2). These coatings should minimize the surface reflection

(in the spectral range 350-1100 nm) to less than 0.4 percent on all surfaces. Design

reflectance curves and measurements on witness samples are to be provided to SAC.

Coating samples of ~25mm diameter, three (03) numbers shall be supplied to SAC

before actual coating of lenses.

2.5 Reflective Coating

Specified zones (refer annexure 2) shall be coated with metallic coatings (enhanced

Aluminium or Protective silver preferably). This coating should meet the reflectance

specifications given in Tables 3.1.12. The protective layer used shall be validated on

the substrate. The witness samples of the coatings shall be fabricated along with

hardware in conformity with relevant MIL – standards and shall be verified through

tests on witness samples. Reflectance measurements shall be carried out through CaF2





glass with 5 mm material thickness. Test conditions will be worked out by manufacturer

in consultation with SAC.

After coating qualification, deposition of coatings is to be carried out by vendor as per

the specifications provided in RFP. These coatings should maximize the surface

reflection in the spectral range of 400 - 900 nm. Average reflection should be more than

88% for all surfaces over the spectral range.

2.6 Black Painting

Lenses are to be black painted (at specified zones) to reduce stray light (refer annexure

2). The paint to be used should be vacuum compatible. Black painting details are

provided in annexure 2.

Two of the available products are:

Supplier 1 MAP, Z.I Rue Ciement Ader, 09100 Pamiers, France

Items: PU1 black paint (1 kg pack) + PU1 thinner (1 litre pack) + Phosmap 11

primer (1 litre pack) + Phosmap 11 thinner (1 litre pack) + middle

plywood box.

Supplier 2 Lord Corporation, Chemical products, 2000 West Grandview Blvd,

P.O. Box 10038, Erie, PA 16514, United States.

Items Aero glaze Z306 Quart + Aero glaze 995824a quart.

The black paint should be applied according to the instructions of the selected

manufacturer.

5 samples of 75mm x 75mm x 3 mm thick BK7 / CaF2 should be provided to SAC

before painting of actual lens cells, barrel and spacers. After getting clearance from

SAC, painting of lenses should be started.





SECTION III

SPECIFICATIONS OF FRONT AND REAR SURFACES

OF ORIGAMI LENS

3.1 To meet design specifications, a four-reflection lens design in CaF2 is optimized

in ZEMAX. Our four-reflection lens design, shown in Figure 1, is an annular

reflective lens utilizing four concentric aspheric reflectors to focus incoherent

light to an image plane in near alignment with the back-side of the lens.

This section gives the optical specifications of an Origami lens in table below.

The tolerances on each of these specifications are also given.

TABLE 3.1

Please refer to Annexures for details

SPECIFICATIONS OF 4-FOLD ORIGAMI LENS

Please refer to Figure 1 for drawing of this multi-fold lens

S.No. PARAMETER SPECIFICATION

1. Material CaF2

2. Surface As per the Surface Sag

specifications / ZEMAX® design

given in Annexure -1 for all 4

bands B1 – B4

3. Shape of the Lens Circular

4. Physical Diameter Between 70.00mm and 75.00 mm

5. Clear Aperture 65.00mm (Refer Annexure 1 and 2

for details)

6. Surface Profile Aspheric (Both at front and rear)

(Refer Annexure 1 and 2 for

details)

7. Circularity at Edges

Mounting Surface Finish

Within 1 micron

Shall be finished to Emery 303 (or

equivalent)

8. Chamfering Sharp edges of the lens shall be

chamfered to around 0.5mm

9. Surface Figure (Over the Full Active

Area) Better than /6 Peak-to-Valley





/35 RMS, → 632.8 nm (He-Ne)

10. Scratch/Dig 60/40 or better

11. Surface Roughness Less than 5 nm

12. Reflectance

At all Angles of Incidence

Enhanced Al Coating / Silver Coating

(mutually agreed upon) with an

additional Protective Overcoat over the

entire active area

Average ≥ 88%

(0.4 – 0.9 microns)

Measurement of reflectance to be

carried out through CaF2 glass with

5 mm thickness of material.

(refer section 2.5)

13. Coating Pinholes There should be no pinholes visible

in the coating when it is

illuminated by a bright source of

light / backlit (As per relevant MIL

standard)

14. Coated Area Please refer Annexure 2

15. Tolerance on Coated Area (For

S.No.14.)

±50 microns

16. Coating Thickness Uniformity Better than 1 percent (desirable)

17. Uncoated Area (Annular Aperture for

Light Input, Rear Central Portion for

Light Exit)

Please refer Annexure 2

18. Black Painted Area

Qualified black paint shall be used.


19. Anti-Reflection Coating Anti-reflection coating on

uncoated area with less than 0.4%

reflection over spectral range 0.35

– 1.1 microns. (Please refer

Annexure 2 and section 2.4)

Note: The optics shall meet the required performance as stated in Table above for a thermal

environment of 20 ± 3°C. In addition to this, the system shall withstand a storage temperature

range from 10° C to 50°C.





SECTION IV

FINAL SPECIFICATIONS OF ORIGAMI LENS

4.1 This section gives the optical specifications as a complete lens after the

completion of fabrication through diamond turning process, coating and black paint.

These parameters will be tested by the fabricator and/or at SAC. It is to be ensured that

the specifications of the completed lens (after lens turning, coating and black painting)

meet the specifications mentioned in table 1.1 within the specified tolerance values

(Annexure 3).

In case, the numbers do not match within the given tolerances, the fabricator will have

to re-fabricate the lens to meet the desired specifications (in consultation with SAC).

The final specifications of the lens would be provided at the time of placement of the

purchase order.

The specifications are given in table 4.1 below. The ZEMAX listing is provided in

Annexure 1 for all the bands as mentioned in the RFP Document.

The lens has to be fabricated using single-point diamond turning machine on CaF2

material as per the specifications given in Section III, meeting the quality and

performance specifications as laid down in the RFP.

TABLE 4.1

SPECIFICATIONS FOR THE ORIGAMI LENS: LENS

PERFORMANCE PARAMETERS

S.No. PARAMETER SPECIFICATION

B1 B2 B3 B4

1. Effective Focal Length 67.5 mm ± 1 mm

2. F/Number (Effective) 1.85

3. Field Of View ± 6.8°

4. Image format (mm) > 16

5. Thickness (Centre of the

Lens) (in mm)* 19.603 19.586 19.437 19.438

6.

Lens Vertex (measured

from center) to Image

Plane Separation (in

mm)*

2.518

± 0.2

2.5015

± 0.2

2.508

± 0.2

2.520

± 0.2

7. Design MTF, 50 lp/mm 0.39 0.43 0.49 0.47





8. MTF (Realizable, Post

Fabrication)*

(at 50 lp/mm)

0.28 0.32 0.38 0.35

9.

Spectral range

(a) Central wavelength

(nm) 485 555 650 815

(b) Half Power Band

Width (nm) 70 70 60 90

10. Average transmission

(%) (400 – 900 nm) > 50% (at final lens level, all bands)

* Final details to be provided at the time of order placement

Note: All the parameters during and/or after environmental test shall be measured at

a fixed distance from the flange chosen for initial measurement.

MTF measurement shall carried out in sagittal and tangential directions for all field

points as per following table

MTF measurement at various along and across track field angles

Across track

field 6.80 3.4 0 -3.4 -6.8





SECTION V

QUALITY PROVISIONS

5. 1 Quality Assurance Requirements

Quality assurance requirements consist of

Space qualified material selection and qualification.

Ensuring that the optical components withstand a thermal environment from

−20°C to +60°C without affecting the performance when brought to ambient

The process qualification and control.

Qualification and acceptance test requirements.

Contamination control.

Vendor shall carry out qualification testing on witness samples for coating

qualification, described in the successive sub-sections of this document. The

supplier/vendor should provide the reflection and transmission data for reflective & AR

coating on witness samples in the form of EXCEL files after the design is completed,

but before the actual coating starts.

5.1.1 Material

The material used for fabrication of the lens shall be of space/military grade. The

substrate material used for fabrication of the lens shall be free from strain, internal

stresses and internal defects. The material from the same batch shall be used for

fabrication of all the components including witness samples.

Materials, which are nutrients for fungus, shall not be used. Materials used shall be of

low out gassing type with TML





5.1.3 Surface Quality

The optical surfaces shall have of cosmetic defects such as digs, scratches, pits, pin

holes and sleeks as per MIL-PRF-13830B. The permissible tolerance for scratches and

digs shall be 60-40.

5.1.4 In-process Quality Control Requirements

The manufacturer shall ensure the quality control for realizing a high quality product.

Manufacturer shall provide fabrication flow chart with Key Inspection Points (KIP).

The quality control shall also include, but not limited to, the following process

qualification details of coating, diamond turning etc.

A detailed quality control document shall cover:

- List of proposed materials with outgassing details and material vendors.

- Configuration control.

- Traceability includes batch number, fabrication lot number and component

identification.

- Cleanliness control.

- Process qualification details of coating.

- Non-conformance plan.

Non-conformance at any stage, which affects the quality and reliability of the product,

should be immediately reported to SAC and the required clearance shall be taken from

SAC. This data should be recorded and made available as and when required.

5. 2 Qualification Tests Requirements

Only qualified processes shall be adopted while fabricating the lens. The qualification

test level & test matrix for coating qualification (both Reflective & Anti-reflection)

is given in Table 5.1 & Table-5.2. Minimum size of Witness Samples (WS) would be

1 inch. The methods and procedures for measurement of parameters along with the test

equipment, their calibration and individual parameter limits should be communicated

prior to qualification exercise.

Table 5.1: Test Matrix for qualification of coating on witness samples

Sr. No.

WS 1

WS 2 WS 3 WS 4

1 VI,SR VI,SR VI,SR VI,SR

2 Cold Storage Humidity Thermal Cycle Thermal Shock





3 Hot Storage VI,SR VI,SR VI,SR

4 VI,SR Abrasion Adhesion -

5 - VI VI -

Table 5.2: Test Levels

Tests For Coating Qualification on

Witness

(AR & Reflective Coating)

For Lens acceptance

Cold Storage Temp: - 20º ± 1º C;

Duration: 24 hrs.

Temp: - 20º ± 1º C;

Duration: 24 hrs.

Hot Storage Temp: 60º ± 1º C;

Duration: 24 hrs.

Temp: 60º ± 1º C;

Duration: 24 hrs.

Humidity R.H. 95%

Temp: + 50º C

Time: 24 hrs

-

Thermal Cycling Temp: - 20º to + 60º ± 1º C;

Dwell time: 2hrs ± 5 min

Transition rate: 3°C /min

No. of Cycles :10

Temp: 0º to + 50º ± 1º C;

Dwell time: 2hrs ± 5 min

Transition rate: 3°C /min

No. of Cycles :3

Thermal Shock Temp: - 20º to + 60º ± 1º C;

Dwell time: 5 min

No. of Cycles :200

-

Adhesion As per MIL 13830/ MIL-C-675 -

Abrasion As per MIL 13830/ MIL-C-675 -





SECTION VI

TEST REQUIREMENTS Tests shall be conducted to verify the fabrication, workmanship and performance of the

lenses. Proper test setup(s) need to be made (in consultation with SAC) to ensure

measurement accuracies. Fabrication and testing of the lens is the responsibility of

supplier.

The parameters to be measured at component level of lens fabrication/testing are given

below: -

Table 6.1 Performance compliance matrix

S. No Parameter Specification

1. Material properties Procurement

2. Thermal cycling for stress relieving Before coating

3. Radius of curvature / Conic of all surfaces Before coating

4. SAG data Before coating

5. All physical dimensions Before coating

6. Surface quality (Scratch/dig) Before coating

7. Surface roughness Before coating

8. Surface figure Before coating

9. Reflectance & Transmission Witness sample

10. Clear Aperture After coating

The supplier shall submit the methods and procedures of all the tests for measurement

of parameters to meet the specifications. All the results at fabrication level and at post-

fabrication test level shall be provided to SAC in both hard and soft copies. The final

performance parameters with tolerances after achieving the required performance shall

be measured and provided.

6.1. Test Results Properties of the materials (physical, chemical and optical) used for optical component

fabrication and compliance certificates shall be supplied to SAC. The supplier should

provide details of the measurement set-ups as well as the measurement conditions along

with the appropriate data and the digital data in Excel format of the qualified/accepted

component level measurements along with results of witness samples (before and after

each qualification test).


The optical design of the multi-fold lenses presented in this RFP is the proprietary work of Space Applications Center (ISRO) and shall not be used for any other purpose except for preparation of the offer for fabrication.

After fabrication of lens, following environmental tests shall be carried out for acceptance of the lens. Test levels are as per Table-2.

Table 6.2: Test Plan & Test Matrix

SR.

No Test

VI

(Note 1)

All

parameters of

tables 4.1 / 6.1

(Note – 2)

T MTF

(Note 3) COLL Remarks

1 Initial Bench Test at Ambient X X X X X

2 Storage Test

Post Cold

Post Hot

X

X

X

X

X

X

Note – 3

3 Post Thermal Cycling Test /

Final Bench Test at Ambient X X X X X Note – 3

Notes of Table 6.2

Note 1 Visual inspection for holes, digs, bubbles, breakage, deformation, scratches, stresses, peeling of coatings, etc.

Note 2 For testing the parameters of the optics, optical equivalent of detector window, shall be placed near focal plane. The parameters that

shall be measured are EFL, image format, spectral characteristic, transmission, MTF (in 5 planes for each band), collinearity, mechanical

parameters and weight.

Note 3 Parameters of optics shall be measured at ambient conditions.




ABBREVIATIONS:

VI = Visual Inspection

EFL = Equivalent Focal Length

T = Transmission

MTF = Modulation Transfer Function

COLL = Collinearity

6.2. Rework criteria

If the supplier observes deviations from the specifications at any stage, the rework

criteria required to meet the specification, shall be provided by the supplier with proper

justification and analysis for approval of SAC before proceeding further.

6.3. Shelf life

The lens should meet the performance parameters in the standard lab conditions without

any severe degradation of performance. The manufacturer shall also specify the storage

conditions necessary to ensure the shelf life. Procedures to be adopted for cleaning shall

be specified.

6.4. Acceptance / Rejection Criteria The components shall retain their environmental durability & mechanical integrity and

shall not visually show any sign of chipping, cracking of glass/coating. The acceptance

of final product is based upon its compliance with all the specifications/requirements

laid down in the previous sections.





SECTION VII

DOCUMENTS REQUIRED

7.1 Document details

The documents shall include the following:

Declared material list

Certificates for all the materials

Optical parameters of all the materials used for fabrication

Fabrication plan, particularly addressing the procedure and method of realization including processes to be used for coating annular zones

Detailed test procedure to measure surface quality of the component.

Description of test facilities, environmental conditions and operational details

Failure criteria, test termination criteria etc.

List of equipment, needed for functional test and full performance test and their calibration details.

Procedure to measure Surface Sag on Aspheric Surfaces.

Cleaning procedure for the coated surface of lens.

Storage, cleanliness control, packaging, handling details.

7.2 Non – Conformance Report

This shall contain any non-conformance to the specifications of components and optics.

These are to be immediately reported as soon as they are observed.





SECTION VIII

DELIVERABLES AND PACKAGING

8.1 Deliverables

Total Deliverables One (1) Origami Lens each for all 4

bands B1 – B4 meeting the RFP

specifications (Total 4 nos. of lenses)

Witness samples Three (03) pieces of 1” diameter with

each coating batch for each type of

coating (AR & Reflective). Total 6 nos.

A single supplier has to provide all the components given in the sections above.

All documents required as per details given in section VII.

8.2 Packaging

The Origami Lens shall be packed carefully in order to protect it from damage during

transit. Each individual package and their intermediate package shall be fixed within

the shipping package which shall be resistant to mechanical shocks, humidity and dust.

Specific care has to be taken to protect the reflective coating on the optics.

The documentation shall be enclosed in the shipping package.

8.3 Delivery Schedule

The schedule for the supply of the origami lens shall be as follows

1. Placement of Purchase Order T0

2. Delivery of coating samples T1 (T0 + 45) days

3. Delivery of Origami lens T1 + 75 days

*To will be date of Order Placement and receipt of order by the vendor

*T1 will be date of go ahead after performance verification from SAC (Typically around 30 -45 days from date of receipt of coating samples / test optics)

8.4 Warranty: One Year Standard Warranty for optics





General Instructions

General Instructions, terms and conditions

1.1 Vendor should send the offer in duplicate.

1.2 The offer including discount if any, should be valid for at least 120 days

from the date of opening / due date of the tender.

Vendor should fill up compliance against each of the requirements mentioned in

Annexure 5 and all sections of RFP and submit along with the proposal. Providing

incomplete / no details on any point shall be treated as non-compliance.




ANNEXURE – 1

Design / Sag Specifications – Band 1

Zemax Listing

Specifications Details

Entrance Pupil Diameter 65 mm (82.7% Obscured) Temperature 20°C Pressure 1 atm Max. Radial Field ±6.8 degrees Wavelength (Primary) 485 nm

# Comment Type Radius Thickness Glass Diameter Conic Aspheric A4 Aspheric A6 Aspheric A8 Aspheric A10 Aspheric A12

OBJ STANDARD Infinity Infinity 0 0.000 - - - - -

STO STANDARD Infinity 0.0000 65 0.000 - - - - -

2 Input Ap. STANDARD Infinity 20.092 CAF2 65 0.000 - - - - -

3 Zone 1 EVENASPH -106.949 -16.916 MIRROR 67.37318 -1.700 -2.97144805E-07 -5.47394030E-10 8.65130879E-13 -5.85597446E-16 1.46859969E-19

4 Zone 2 EVENASPH -188.419 16.597 MIRROR 47.57645 -3.000 -3.83031949E-06 1.38914520E-09 3.13253348E-13 -5.57617554E-15 2.79196783E-18

5 Zone 3 EVENASPH -488.598 -19.737 MIRROR 49.0809 -3.000 -7.12033951E-06 5.88786820E-09 -8.11287761E-12 7.32946921E-15 -3.02246178E-18

6 Zone 4 EVENASPH -144.493 19.603 MIRROR 23.92666 -3.000 -1.53946195E-05 -1.62017755E-08 -7.77873420E-11 5.88634286E-14 -6.78092625E-16

7 EVENASPH Infinity 0 CAF2 17.99427 0.000 - - - - -

8 Back Working Margin STANDARD Infinity 1.068 17.99427 0.000 - - - - -

9 Detector Window STANDARD Infinity 0.7 D263TECO 17.54539 0.000 - - - - -

10 STANDARD Infinity 0.75 17.35515 0.000 - - - - -

IMA Image STANDARD Infinity 17.07213 0.000 - - - - -





Zemax Listing







3 Zone 1 EVENASPH -105.496 -16.906 MIRROR 67.37323 -3.000 -4.83019304E-07 -1.69683651E-10 3.19441933E-13 -2.35951972E-16 6.24211069E-20

4 Zone 2 EVENASPH -178.850 16.562 MIRROR 47.57885 3.000 -3.41012616E-06 1.93156262E-09 -3.37121442E-12 7.34248562E-16 -8.60890407E-19

5 Zone 3 EVENASPH -470.297 -19.721 MIRROR 49.06208 3.000 -6.90423944E-06 5.19434669E-09 -6.72838264E-12 5.89868441E-15 -2.44171406E-18

6 Zone 4 EVENASPH -144.816 19.586 MIRROR 23.94057 3.000 -1.50155155E-05 -1.71097673E-08 -7.28694727E-11 8.24723653E-14 -8.33851220E-16

7 EVENASPH Infinity 0.0000 CAF2 17.97689 0.000 - - - - -









Zemax Listing







3 Zone 1 EVENASPH -104.216 -16.8000 MIRROR 67.35033 -1.541 -3.6115486E-07 3.2111650E-11 -1.4831400E-14 -1.9620443E-17 1.0132446E-20

4 Zone 2 EVENASPH -177.133 16.4120 MIRROR 47.58102 -3.000 -3.3650547E-06 2.1483623E-09 -5.6608943E-12 4.8844096E-15 -3.4243168E-18












Zemax Listing








4 Zone 2 EVENASPH -168.716 16.390 MIRROR 47.59015 -3.000 -3.10531082E-06 2.46202305E-09 -8.16807563E-12 9.23671280E-15 -5.90787755E-18








The final design specifications for all bands shall be provided at the time of order placement.





ANNEXURE – 2

COATING / BLACK PAINT ON LENS: SPECIFICATIONS

Front Surface:

The specifications are given below for the front surface:

Figure A.1: Schematic showing the metal-coating and black-paint details for front

surface of the multi-fold lens





Specifications for Band-1: Front*

Figure A.2: Coating Details

Table A.1: Specifications for Coating and Black-paint for the front

surface of the lens

S.No. Start (Radial,

mm)

End (Radial,

mm)

Specifications

1. 0 12.4 Coated Region

2. 12.4 15.3 Black-Painted Region

3. 15.3 24.3 Coated Region


5. 26.85 32.5 Input Aperture (Anti

reflection coated)

6. 32.5 35 Black-Painted Region * Final details shall be provided at the time of order placement

35 mm 32.5 mm

26.85 mm

24.3 mm

15.3 mm

12.4 mm








surface of the lens


mm)

End (Radial,

mm)

Specifications






reflection coated)


35 mm 32.5 mm

26.85 mm

24.3 mm

15.2 mm

12.45 mm








surface of the lens


mm)

End (Radial,

mm)

Specifications






reflection coated)


35 mm 32.5 mm

26.85 mm

24.3 mm

15.2 mm

12.4 mm








surface of the lens


mm)

End (Radial,

mm)

Specifications






reflection coated)


35 mm 32.5 mm

26.85 mm

24.3 mm

15.2 mm

12.55 mm





Rear Surface:

The specifications for the rear surface are given below:

Figure A.6: Coating details for the rear surface





Specifications for Band - 1: Rear*


Table A.5: Specifications for Coating and Black-Paint for the rear surface

of the lens


mm)

End (Radial,

mm)

Specifications

1. 0 9.4 Anti reflection coated

region (Output from

Lens)


3. 24.85 25.35 Black Painted region

4. 25.35 34 Coated Region

5. 34 35 Black Painted Region * Final details shall be provided at the time of order placement

35 mm 34 mm

25.35 mm 24.85 mm

9.4 mm








of the lens


mm)

End (Radial,

mm)

Specifications


region (Output from

Lens)


3. 25 25.3 Black Painted region



35 mm 34 mm

25.3 mm 25.0 mm

9.4 mm








of the lens


mm)

End (Radial,

mm)

Specifications


region (Output from

Lens)





35 mm 34 mm

25.4 mm 24.8 mm

9.4 mm








of the lens


mm)

End (Radial,

mm)

Specifications


region (Output from

Lens)





35 mm 34 mm

25.3 mm 24.9 mm

9.4 mm





ANNEXURE – 3

TOLERANCE SPECIFICATIONS

FRONT AND REAR SURFACE:

S.NO. Parameter Specification

1. Thickness ± 5µm

2. Radius of Curvature (Zones) ± 0.02 %

3. Decenter (Zones) ± 2 µm

4. Decenter (Rear w.r.t. Front Surface) ± 2 µm

5. Tilt (Zones) ± 0.2 arc-min

6. Tilt (Rear w.r.t. Front Surface) ± 0.5 arc-min

7. Irregularity 0.5 fringe (→632 nm)

8. Homogeneity (Glass) Better than 1 x 10-5





ANNEXURE – 4

References

1. ‘Ultrathin cameras using annular folded optics’, Eric and Tremblay, Applied

Optics, Volume 46, No. 4, pp. 463-471

2. ‘Relaxing the alignment and fabrication tolerances of thin annular folded

imaging systems using wavefront coding’, Eric and Tremblay, Applied Optics,

Volume 46, No. 27, pp. 6751-6758

3. ‘Ultrathin four-reflection imager’, Eric and Tremblay, Applied Optics, Volume

48, No. 2, pp. 343-354





ANNEXURE – 5

Compliance matrix for RFP (To be filled by vendor with necessary remarks as applicable)

Section Details Compliance by

vendor with remarks

1 Introduction

1.1 Scope

1.2 General description of Origami Lenses

1.3 Applicable documents

1.4 Test Sequence

1.5 Conditions and methods of tests

1.6 Supplier responsibility

1.7 Inspection rights

2.1 Optical / mechanical / thermal requirements

2.2 Scope of Work

2.3 Sequence of Activities

2.4 AR Coating

2.5 Metallic reflective coating

2.6 Black Painting

3 Specifications of front and rear surfaces

3.1 Table 3.1 – Specifications of 4-fold Origami lens

4 Final Specifications of Origami Lens

4.1 Table 4.1 – Specifications – Lens performance

parameters

5 Quality provisions

5.1 Quality Assurance Requirements

5.2 Qualification tests requirements

6 Test Requirements

6.1 Test results

6.2 Rework criteria

6.3 Shelf life

6.4 Acceptance/ Rejection criteria

7.1 Documents required

7.2 Non-conformance report

8.1 Deliverables

8.2 Packaging

8.3 Delivery Schedule

8.4 Warranty





Table 3.1 – Specifications of Origami lens

S.No. PARAMETER SPECIFICATION Compliance with

remarks

1. Material CaF2

2. Surface As per the Surface Sag

specifications / ZEMAX®

design given in Annexure -1 for

all 4 bands B1 – B4

3. Shape of the Lens Circular

4. Physical Diameter Between 70.00mm and 75.00

mm

5. Clear Aperture 65.00mm (Refer Annexure 1

and 2 for details)

6. Surface Profile Aspheric (Both at front and rear)

(Refer Annexure 1 and 2 for

details)

7. Circularity at Edges

Mounting Surface Finish

Within 1 micron

Shall be finished to Emery 303

(or equivalent)

8. Chamfering Sharp edges of the lens shall be

chamfered to around 0.5mm

9. Surface Figure (Over the

Full Active Area) Better than /6 Peak-to-Valley

/35 RMS, → 632.8 nm (He-

Ne)

10. Scratch/Dig 60/40 or better

11. Surface Roughness Less than 5 nm

12. Reflectance

At all Angles of Incidence

Enhanced Al Coating /

Silver Coating (mutually

agreed upon) with an

additional Protective

Overcoat over the entire

active area

Average ≥ 88%

(0.4 – 0.9 microns)

Measurement of reflectance to

be carried out through CaF2

glass with 5 mm thickness of

material.

(refer section 2.5)

13. Coating Pinholes There should be no pinholes

visible in the coating when it is

illuminated by a bright source of

light / backlit (As per relevant

MIL standard)





14. Coated Area Please refer Annexure 2

15. Tolerance on Coated Area

(For S.No.14.)

±50 microns

16. Coating Thickness

Uniformity

Better than 1 percent (desirable)

17. Uncoated Area (Annular

Aperture for Light Input,

Rear Central Portion for

Light Exit)


18. Black Painted Area

Qualified black paint shall be

used. Please refer Annexure 1

19. Anti-Reflection Coating Anti-reflection coating on

uncoated area with less than

0.4% reflection over spectral

range 0.35 – 1.1 microns.

(Please refer Annexure 2 and

section 2.4)

TABLE 4.1

SPECIFICATIONS FOR THE ORIGAMI LENS: LENS

PERFORMANCE PARAMETERS

S.No. PARAMETER SPECIFICATION Compliance

with remarks

B1 B2 B3 B4

1. Effective Focal

Length 67.5 mm ± 1 mm

2. F/Number (Effective) 1.85

3. Field Of View ± 6.8°

4. Image format (mm) > 16 mm

5. Thickness (Centre of

the Lens) (in mm)* 19.603 19.586 19.437 19.438

6.

Lens Vertex

(measured from

center) to Image

Plane Separation (in

mm)*

2.518

± 0.2

2.5015

± 0.2

2.508 ±

0.2

2.520 ±

0.2

7. Design MTF, 50

lp/mm 0.39 0.43 0.49 0.47





8. MTF (Realizable,

Post Fabrication)*

(at 50 lp/mm)

0.28 0.32 0.38 0.35

9. Spectral range

(c) Central

wavelength (nm) 485 555 650 815

(d) Half Power Band

Width (nm) 70 70 60 90

10. Average transmission

(%) (400 – 900 nm) > 50%




ANNEXURE – 6

Mechanical Drawings

(Final details to be provided at time of order placement)