林恭如 Gong-Ru Lin

Professor, Department of Electrical Engineering, National Taiwan University

Major Research Areas:

Si Nanophotonics, Femtosecond Fiber Lasers, All-Optical Communication Data Processing

Research Summary:

    We concentrate our research on developing versatile specific synthesizing processes for Si nanostructures and related devices, investigating the physical mechanisms behind the material, electrical, and optical aspects of the Si nanodots, nanopyramids and nanopillars. The targets are implementing Si nanophotonic devices based on quantum confinement effect, and discuss in more detail the origin of the enhancement on radiation/detection, solar energy conversion, and surface plasmonic resonance at blue-green wavelength region. A future collaboration with Academia Sinica on the ab initio atomic potentials based boundary integral Green function for the quantum computation of Si quantum dots with atomic numbers ranging between 103-104 will be initiated to study the electrical property of Si nanocrystals. These simulations will be helpful to elucidate the carrier transport and penetration between Si nanocrystals and neighborhood dopants, and to realize the surface plasmonic wave interaction between Si nanostructures and biomoleculars. Several featured researches including ultra-low threshold ICP power PECVD synthesis for Si nanopyramids, CO2 laser based rapid thermal annealing for precipitating Si nanocrystals, rapid self-aggregated metallic nanodot array for SPR or nano-lithographical applications will be introduced in the following sections.

     On the other hand, we are interested in fundamental and technical study of fiber laser schemes for potential applications on ultrafast optoelectronic diagnosis, high-speed fiber-optic communications, and biophotonic or biomedical analysis, etc. Over past years, we have constructed several types of continuous-wave and shorted-pulsed Erbium-doped fiber amplifier or semiconductor optical amplifier based fiber ring lasers.  In particular, we have theoretically simulated and experimentally established an optical injection mode-locked semiconductor optical amplifier fiber laser system, which exhibits femtosecond pulsewidth after external soliton compression and facilitates high-repetitive low-supermode-noise output. The other milestones of our works include 40th-oeder rational harmonic mode-locking of EDFL using a FPLD based mode-locker, mutual injection-locked EDFL/EDFL and FPLD link, tipped fiber based low-splicing-loss fusion technology between different fibers, >10GHz backward optical injection induced cross-gain-modulation for mode-locking, etc. In brief, the distinguished researching fields on Si nanophotonics, fiber lasers, and all-optical communication data processing likes are emphasized in our laboratory, which include:

 

A. Nanocrystallite Silicon SiCx, SiNx or SiOx Based LEDs and Solar Energy Photonics

 

 

B. Femtosecond Mode-Locked Fiber Lasers and Soliton Compressors

C. All-Optical OC-192 NRZ/RZ BPSK/OOK Communication Data Format Processing

D. Injection-Locked Laser Diode or Semiconductor Optical Amplifier Based Fiber-Optic WDM-PON

E. Millimeter-wave Optoelectronic Phase-Locked Loops and Phase Shifters