Browsing by Author "Wu, Yu-Chang"

Now showing 1 - 6 of 6

Compact Photonic Integrated Chip for Tunable Microwave Generation
(2014-03-01)
Chien, Chen-Yu
;
Lo, Yen-Hua
;
Wu, Yu-Chang
;
Hsu, Shun-Chieh
;
Tseng, Hung-Ruei
A tunable microwave generation is demonstrated by monolithically integrated photonic chip, which combines a mirror section and two distributed feedback (DFB) lasers. The focus ion beam technology was employed to achieve high-quality air/semiconductor slab for the mirror. Two DFB lasers (named slave and master lasers, respectively) can operate in a single fundamental mode when they are individually pumped. A microwave signal with the differential frequency between the two lasers can be obtained through optical heterodyning. A tunable microwave signal up to 25.5 GHz can be generated by adjusting the injected currents of the two DFB lasers. A four-wave mixing spectrum was measured and the linewidth of the generated radio frequency signal is 1.9 MHz.
Design of III-V/Silicon hybrid surface-emitting laser with grating structure
(2015)
Huang, Jen-Hung
;
Chen, Bai-Ci
;
Wu, Yu-Chang
;
Lin, Chien-Chung
;
光電系統研究所
The VCSEL consisting of the HCG mirror, an active layer with InGaAsP quantum wells having optical gain around 1.31 mu m and a TiO2/Sio(2) DBR is designed. Small threshold gain can be theoretically gotten by adjusting the thickness of BCB layer and N-InP layer.
Evaluation of Tunable Microwave Signals Generated by Monolithic Two-section Distributed Feedback Lasers
(2013-01-01)
Lin, Chien-Chung
;
Chien, Chen-Yu
;
Wu, Yu-Chang
;
Kuo, Hao-Chung
;
Lin, Chun-Ting
We demonstrated a two-section 1.55 mu m laser with an air gap in the middle section. When two DFB lasers are powered together, an optical heterodying operation can produce microwave signals up to 44 GHz.
Low-Temperature Direct Wafer Bonding for III-V Compound Semiconductors to Nanometer-scale Grating Arrays
(2015)
Chen, Bai-Ci
;
Wu, Yu-Chang
;
Huang, Jen-Hung
;
Kuo, Hao-Chung
;
Lin, Chien-Chung
In this paper, we designed the grating with different periodicities on silicon. Aluminum or silicon dioxide would be filled in the inter-space of grating. Besides, the surface reflectivity of different structures was measured and the theoretical calculation was performed. By oxygen plasma-enhanced process, we successfully present the results of a low-temperature process for direct bonding of InP epitaxial layers on a silicon wafer.
Numerical Analysis on V-shape Gratings for III-V/Silicon Hybrid Lasers
(2015)
Huang, Jen-Hung
;
Chen, Bai-Ci
;
Wu, Yu-Chang
;
Lin, Chien-Chung
;
光電系統研究所
We propose and numerically analyze a novel sub-wavelength grating for the purpose of III-V/silicon integration. The design is based on different shapes of gratings in order to increase the lateral (or sideway) coupling. By using COMSOL (R) as the platform, the reverse V-grating design can have doubled percentage of optical field into the silicon grating region when compared to reference. However, the threshold gain of this design is still high and further optimization is needed.
Tunable microwave generation of a monolithic dual-wavelength distributed feedback laser
(2014-06-02)
Lo, Yen-Hua
;
Wu, Yu-Chang
;
Hsu, Shun-Chieh
;
Hwang, Yi-Chia
;
Chen, Bai-Ci
The dynamic behavior of a monolithic dual-wavelength distributed feedback laser was fully investigated and mapped. The combination of different driving currents for master and slave lasers can generate a wide range of different operational modes, from single mode, period 1 to chaos. Both the optical and microwave spectrum were recorded and analyzed. The detected single mode signal can continuously cover from 15GHz to 50GHz, limited by photodetector bandwidth. The measured optical four-wave-mixing pattern indicates that a 70GHz signal can be generated by this device. By applying rate equation analysis, the important laser parameters can be extracted from the spectrum. The extracted relaxation resonant frequency is found to be 8.96GHz. With the full operational map at hand, the suitable current combination can be applied to the device for proper applications. (C) 2014 Optical Society of America