ee 231 optical electronics, fall 2003 ee231 optical electronics - class outline class website: ...
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EE 231 Optical Electronics, Fall 2003
EE231 Optical Electronics - Class outline
• Class website: http://www.cse.ucsc.edu/classes/ee231/Fall03/
• Instructor: Claire Gu, BE 253B, [email protected]
• Lecture: Tue/Thu 10-11:45, Stevenson 221
• Office hours: Wed 2-4 pm
• Homework: bi-weekly
• Grading policy:
Course Element Percentage Homework 20 Midterm 20
Project/Term Paper 30 Final 30 Total 100
EE 231 Optical Electronics, Fall 2003
EE231 Optical Electronics - Class outline II
• Midterm: Written, in class
• Final: during the final’s week
• Project:
• investigate class-related subject
• literature review
• problem/calculation
• assigned or student-suggested -> talk to me
• term paper and in-class presentation
• class content: mainly lasers, but we’ll really learn much more:
• optics
• physics
• materials
• systems
EE 231 Optical Electronics, Fall 2003
Electromagnetic Spectrum
}LASER: Light Amplificationby Stimulated Emission ofRadiation
MASER: Microwave Amplificationby Stimulated Emission ofRadiation}
EE 231 Optical Electronics, Fall 2003
Different types of lasers
Free electron laser, UCSB(63 m – 2.5 mm)
VCSEL array:vertical cavitysurface emittinglaser (850 nm)
Ti:Sapphire laser:ultrashort pulses (30 fs)(700-1000 nm)
EE 231 Optical Electronics, Fall 2003
Laser characteristics
• spectrally broad• divergent• can’t be focused tightly• not very intense• incoherent
• very monochromatic• does not diverge as fast• can be focused tightly• can be extremely intense• spatial coherence (interference)• temporally coherent (beat notes)
What is needed ?
More generally:
• active medium• pump -> far from thermal equilibrium• feedback (resonator, mirrors)
EE 231 Optical Electronics, Fall 2003
Laser characteristics II -Threshold
kink inoutput power
spectral narrowing
EE 231 Optical Electronics, Fall 2003
Laser history
1910 1920 1930 1940 1950 1960 1970 1980 1990 2000
Einstein predictsstimulated emission
Townes invents and builds first MASER
Schawlow and Townes propose LASER
Maiman builds first (ruby) LASER
Javan inventsHe-Ne laser
Faist builds quantumcascade laser
Nakamura builds blue laser diode
nanowire laser builtat UCB
Alferov builds first heterostructure laser
CD playerIBM builds first laser printerHall buildssemiconductor laser
Spectra introducesTi:Sapphire laser
first fiber optic communication system (Chicago)
EE 231 Optical Electronics, Fall 2003
Lasers in science
laser coolingand trapping
interferometrylength measurements
biological processes
ultrafast phenomena
EE 231 Optical Electronics, Fall 2003
Lasers in medicine
corrective eye surgery
removing blemishes
gallbladder surgeryusing fiber optics
EE 231 Optical Electronics, Fall 2003
Lasers in every day life
barcode scanners
laser printers• laser cutting• laser welding• ....
CD players
EE 231 Optical Electronics, Fall 2003
Lasers in communication systems
4 PIN receivers
160 km standard fibre
boosteramplifier
4 WDMEA-DFB lasers
pre-amplifier
attenuatorand powermeter
optical spectrum analyser
channel separation: 100 GHz (0.8 nm)
DEMUX
laser as source
laser as amplifier
PIN-diode PIN-diode
Input
Monitor tap
Isolator980/1550 coupler
Er fibre
Isolator Monitor tap Output
980 nmpump laser