Laser Micromachining of Active and Passive Photonic Integrated Circuits
Name
Songho Cho - TR710.pdf
Size
3.57 MB
Format
Adobe PDF
Checksum (MD5)
74ee988ec4f84514ba3159e9ccf36144
Author(s)
Cho, Seong-Ho
Date Issued
June 28, 2006
Series/Report no.
Technical Report (Massachusetts Institute of Technology, Research Laboratory of Electronics)
710
Abstract
This thesis describes the development of advanced laser resonators and applications of laserinduced micromachining for photonic circuit fabrication. Two major advantages of laserinduced micromachining are direct patterning and writing on large areas of substrates at high speed following the exposure of laser light, without using complicated photomask steps. For passive photonic devices fabrication, a novel femtosecond laser with unprecedented low repetition rates of 4 MHz is demonstrated to generate high intensity pulses, as high as 1.25 MW with 100 nJ pulse energies and 80 fs pulse durations directly from this laser resonator, without using any active devices or amplifiers. These high intensity pulses are applied to transparent glass materials to demonstrate micromachining of waveguides, gratings, couplers, and three
dimensional waveguides and their beam couplings.
Active and passive semiconductor devices can be monolithically integrated by employing high energy laser pulses to locally disorder quantum well regions. The 45 nm bandgap shifts at 1.55 µm with a standard Q-switched Nd:YAG laser at 535 nm are realized. Finally, unidirectional
semiconductor ring lasers for high-density integration are developed as a potential
application to photonic integrated circuits. Hybrid semiconductor S-crossover and retroreflected ring lasers, as prototypes for unidirectional operation, are built and result in up to 21.5 dB and 24.5 dB of counter-mode suppression ratio, respectively, which is in good agreement
with theoretical predictions.
Description
Thesis Supervisor: Rajeev J. Ram
Title: Professor
MIT Department
Massachusetts Institute of Technology. Research Laboratory of Electronics
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