Sacher Lasertechnik
Next Generation Littrow
LYNXTM Joachim R. Sacher
(confidential technical documentation)
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Littrow Laser Products
Application Optical Cooling & Trapping Raman Spectroscopy Holography
Award Winning Product CLEO Conference 2000
Cavity Layout
Product Photo
(confidential technical documentation)
Next Generation Littrow Cavity
LaserEmission
WavelengthAdjustment
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Littrow Laser Products – Industrial Grade
Excellent Stability Low Temperature
Drift >3kHz Cavity
Resonace Freq. Narrow Linewidth
<100kHz
(confidential technical documentation)
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Littrow Laser Products – Industrial Grade
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Performance Data @ 780nm 780nm
767nm Temperature Behavior
795nm
(confidential technical documentation)
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Littrow Laser Products – Industrial Grade
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Temperature Cycling
Excellent wavelength stability over >24 hours temperature cycling
No laser stabilization during measurement
Simple compensation via Locking electronics
(confidential technical documentation)
Operation Performance On – Off Repeatability
Excellent repeatability after start-up sequences.
Back to the absorption line within a few minutes after restarting laser current,
no loss of the absorption line
0,0 0,5 1,0 1,5 2,0 2,5 3,0 3,5 4,0 4,5 5,0 5,5793,4010
793,4015
793,4020
793,4025
793,4030
793,4035
793,4040
793,4045
793,4050
Wav
elen
gth
/ nm
Time / hours0 5 10 15 20 25 30
780,024
780,025
780,026
780,027
780,028
22,6
22,8
23,0
23,2
23,4
Tem
pera
ture
(B
asep
late
) / °
C
Wav
elen
gth
/Vac
uum
) / n
m
Time / hours
Full StartupTemp & Current
Partial StartupLaser Current
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Littrow Laser Products – Industrial Grade
Tuning Concepts Mode-Hop Free Tuning
Grating
Grating
Grating
(a)
(c)
(b)
Pivot Point
Grating
Laser
True Pivot Point Selection
Exact Choice of x0, x1, x2
Synchronization Cavity Defined Wavelength Grating Defined Wavelength
Result: Mode-Hop Free Tuning
(confidential technical documentation)
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Littrow Laser Products – Industrial Grade
Tuning Concepts
Ricci & Hänsch Littrow Cavity Concept *
* L. Ricci, M. Weidemüller, T. Esslinger, A. Hemmerich, C. Zimmermann, V. Vuletic, W. König, T.W. Hänsch, A compact grating-stabilized diode laser system for atomic physics, Optics Communications 117, page 541-549, June 1995
Littrow Cavity Compromise Favoring High Frequency Cavity
Resonances over Mode-Hop Free Tuning
Result: Virtual Pivot Point Concept
Problem Insufficient Cavity Length Variation
during Piezo Scan of Cavity Gratingdue to Virtual Pivot Point Concept
Solution Enhancement of Mode-Hop Free via
Synchronious Piezo – Laser CurrentModulation
Change of Laser Current changesthe Optical Path Length of Laser Diode due to Electro-Optic Effect
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Littrow Laser Products – Industrial Grade
Tuning Concepts Virtual Pivot Point
Virtual Pivot Point 2
Synchronization Cavity Defined Wavelength Grating Defined Wavelength Laser Current with Piezo Voltage
Result: Enhanced Mode-Hop Free Tuning
Grating
Laser
Pivot Point 1
Rotation
Pivot Point 2
Tuning Results Piezo Fine Scan
Rubidium Absorption
Result: Full Mode-Hop Free Tuning Limited by Piezo Actuator
0 500 1000 1500 2000
780,908
780,910
780,912
780,914
780,916
780,918
780,920
780,922
780,924
780,926
Wav
elen
gth
[nm
]
Time [s]
(confidential technical documentation)
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Littrow Laser Products – Industrial Grade
Linewidth Measurement
Measurement Setup Hetherodyne Beat Setup Laser 1: Littrow Cavity Laser 2: Littrow Cavity
Test Results Hetherodyne Beat Setup Linewidth: <<100kHz
< 15kHz (typ.)
Scan Rate: 1ms / div. RBW: 100kHz
499,0 499,2 499,4 499,6 499,8 500,0 500,2 500,4 500,6 500,8 501,0
70
140
210
Inte
nsity
/ dB
Frequency / MHz
499,0 499,2 499,4 499,60
1x1021
2x1021
Data: Data4_DModel: LorentzEquation: y = y0 + (2*A/PI)*(w/(4*(x-xc)^2 + w^2))Weighting: y No weighting Chi 2/DoF = 1.5411E40R^2 = 0.88367 y0 -2.0046E19 ±1.1603E19xc 499.32448 ±0.0004w 0.01921 ±0.00119A 6.6969E19 ±3.0936E18
2x Littrow, Linear Scale, FWHM = 10 KHz
Frequency / MHz
Inte
nsity
/ a.
u.
(confidential technical documentation)
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Littrow Laser Products – Industrial Grade
Long Term Stability
Measurement Setup System locked to Rb
Reference
Test Results Long Term Stable
(confidential technical documentation)
0 1 2 3 4 5780,220
780,225
780,230
780,235
780,240
780,245
780,250
780,255
780,260
780,265
780,270
780,275
780,280
Laser System locked to Rubidium Reference Laser Wavelength Stability
Time [h]
wav
elen
gth
[nm
]
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Littrow Laser Products – Industrial Grade
Realitive Intensity Noise
Measurement Setup Laser Controller (PilotPZ 500) 20MHz Photoreceiver 12 bit Digital Oscilloscope with FFT
Test Results RIN Spectrum
Laser Driver
Diode Laser
Detector
Oszi
Amplifier
0 100 200 300 400 500 600-140
-120
-100
-80
-60
-40
-20
0
Rel
ativ
e In
tens
ity N
oise
, dB
Littrow Laser S3 RIN spectrum
Frequency, Hz
0 1k 2k 3k 4k 5k-140
-120
-100
-80
-60
-40
-20
0
Rel
ativ
e In
tens
ity N
oise
, dB
Frequency, Hz
Littrow Laser S3 RIN spectrum
(confidential technical documentation)
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Littrow Laser Products – Industrial Grade
Mechanic Cavity Resonance Measurment Setup
Heterodyne Beat Setup Laser 1: Littrow (not modulated) Laser 2: Littrow, 60mV Piezo Modulation Detection: Linewidth Enhancement via Modulation
Mechanic Resonances No resonances below 3kHz 1st resonance 3.4kHz 2nd resonance 4.3kHz
0 1000 2000 3000 4000 50000
5
10
15
20
25
30
35
Fre
quen
cy T
unin
g / M
Hz
Piezo Modulation Frequency / Hz
(confidential technical documentation)
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Low Noise Laser Controllers
Micro Controller Operated Laser Controllers
Sub µA Noise Figure Up to 4000mA Laser
Current Integrated Function
Generator Integrated Piezo
Amplifier Fully Remote Control
Features USB, GPIB, RS232 Laboratory and
OEM Versions
(confidential technical documentation)
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Technology: Micro-Controller & FPGA
Low Noise Laser Controllers
Laser Diode Current Sub µA Noise Figure
102 103 104 105
1E-12
1E-11
1E-10
1E-9
1E-8
Pilot PZ 500 Noise Spectrum
Frequency [Hz]
100mA 200mA 500mA
Cur
rent
Noi
se [A
/ H
z]10 ResistorΩ
DC Current
Electrical Spectrum AnalyzerLaser Controller
(confidential technical documentation)
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Servo Controller
High Frequency PI Regulator 10MHz Bandwidth Adjustable Corner
Frequencies Integration Hold Function Low Frequency Gain Limit FPGA Controlled Operation Fully Remote Control
via USB
Application: Laser Stabilization Optical Cooling & Trapping
Principles of Operation
Product Photo
(confidential technical documentation)
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Modulator & Demodulator
High Frequency Synthesizer Central 3GHz Clock 2 DDS Syntesizer 100kHz to100MHz Modulation ns Phase Adjustment High Frequency Mixer High Modulation Amplitude Fully Remote Control
via USB
Application: Laser Stabilization Pound Drever Hall Lock Optical Cooling & Trapping
Principles of Operation
Product Photo
(confidential technical documentation)
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Application: Optical Cooling & Trapping
Laser Frequency Stabilization Frequency Tolerance <1MHz 24/7 Operation Requirement Locking to Rubidium Transition Locking to Cesium Transion Side of Fringe & Top of Line Lock
Fully Remote Control Operation Internal Operation Control via FPGA Remote Control via USB
ECDLISO PBSλ/2BS
Rb
M
MBS
Wavemeter D1 D2Lockcircuit
(confidential technical documentation)
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Corporate Headquarter
Sacher Lasertechnik Headquarter
Space 1200m²12900 square ft.
30 employees at location
(confidential technical documentation)
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Product Family Overview
Laser Controller Laser Controller Laser Controller
AR Coated Laser Diodes
MOPA Laser System MOPA Laser System
Littrow Laser System Littman Laser System Laser Amplifier System
DFB Laser Diodes
THz Laser System
DFB Laser Diodes
SHG Laser System
ns Pulsed Laser System
ps Mode Locked Laser
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Technology: Thin Film Coating Equipment
Thin Film Coating Equipment
Sputter Coater High Volume
Production R&D Coatings
E-Beam Coater R&D Coatings
(confidential technical documentation)
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Technology: Diode Laser Chip Handling
Dye Bonder Laser Chip Mounting
Wire Bonder Laser Chip Electrical Connection
(confidential technical documentation)
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Technology: Electro Optic Micro-Assembly
Multi-Emitter Fiber Coupling
Up to 12 Single Mode Emitters Fiber Coupled
Multi-Wavelength Emitter Fiber Coupled
(confidential technical documentation)
Micro External Cavity
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Technology: Electro Optic Micro-Assembly
Compact Package Excellent Stability No Moving Parts No Mechanic Cavity
Resonances Narrow Linewidth Low Temperature
Drift
(confidential technical documentation)
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Thank You For Your Attention!
Sacher Lasertechnik GmbHRudolf-Breitscheid-Str. 1-535037 MarburgGermany
Sacher Lasertechnik LLC.5765 Equador WayBuena Park, CA 90620United States
http://www.sacher-laser.com© 2009 Sacher Lasertechnik GmbH. All rights reserved.