continued Advanced Semiconductor Lab

New Materials Strong temperature sensitivity ← Insufficient electron confinement in the active region Insufficient variation of refraction index in InGaAs/InP ← severe problem in the formation of distributed Bragg reflectors for vertical cavity surface emitting lasers (VCSELs) Quantum well structure 로는 필요한 파장 range를 얻지 못한다.  Emerge Quantum Dot, InGaAsN, InNAsP, etc.

7.4 Mode power distributed feedback lasers Solution of incident and reflection Reflectance for corrugation at z=0 Under phase matching conditions, △β Semiconductor optoelectronic devices, by P. Bhattacharya

Semiconductor optoelectronic devices, by P. Bhattacharya

7.5 Cleaved-Coupled-Cavity(C3 ) laser Semiconductor optoelectronic devices, by P. Bhattacharya

Injection-locked Laser C3 Laser Injection-locked Laser Semiconductor optoelectronic devices, by P. Bhattacharya

7.6 Quantum well laser Semiconductor optoelectronic devices, by P. Bhattacharya

Band diagram of the active region Semiconductor optoelectronic devices, by P. Bhattacharya

Strained Quantum Well Lasers Semiconductor optoelectronic devices, by P. Bhattacharya

7.7 Surface-Emitting Laser Semiconductor optoelectronic devices, by P. Bhattacharya

7.10 Device fabrication Broad-area laser by cleaving Ridge lasers are defined by photolithography and wet or dry etching Semiconductor optoelectronic devices, by P. Bhattacharya

7.11 measurement of laser characteristics Differential gain Near-and far field patterns Usually, the fabricated laser is mounted on an efficient heat sink. For high performance operations, a feedback circuit and thermoelectric cooling are provided. It is common to determine the laser characteristics under pulsed biasing conditions. Semiconductor optoelectronic devices, by P. Bhattacharya

Linearity of light current characteristics Modulated output power P(t) = P0 [1+ms(t)] Modulation index, Harmonic distortion Intermodulation distortion light-current characteristics should be as linear as possible. Semiconductor optoelectronic devices, by P. Bhattacharya

7.16 Long-wavelength semiconductor laser Lead-salt or lead chalcogenide lasers Population inversion can be achieved by using resonant tunneling Tuning by changing the well and barrier parameters Semiconductor optoelectronic devices, by P. Bhattacharya