All-optical clock recovery (AOCR) for 100 Gb/s RZ-OOK signal is demonstrated by using a dualmode beating DBR laser. Based on the injection-locking of the DBR (distributed Bragg reflector) laser, a 100-GHz optical clock is recovered. Timing jitter (<1 ps) derived from both phase noise and power fluctuation is measured by an optical sampling oscilloscope (OSO). Furthermore, clock recovery is also realized for the 100 Gb/s signal after 25 km transmission. After the 25-km SMF (5- dB loss) transmission, the signal-to-noise ratio (SNR) of the signal drops from 18 dB to 5.2 dB. The dependence of the timing jitter on the input power is investigated. The lowest timing jitter of 665 fs is realized when the input power is 3 dBm.
A novel mode-beating DBR laser with dual-mode lasing is fabricated. The DBR laser has four parts, a front gain section, a phase section, a DBR grating section, and a rear gain section. When the current of the front gain section is above the threshold, the device is working in single-mode. Dual-mode lasing can be obtained by adjusting the current of the rear gain section. The power difference between the two modes can be less than 1 dB. An optical down-conversion technique was used to measure the beating frequency. The mode-beating frequency of the two modes is about 93 GHz, and the 3- dB linewidth of the mode-beating RF spectrum of the laser when free-running is about 5 MHz. Moreover, the wavelength of the dual-mode can be tuned synchronously when the current injected into the DBR grating section is adjusted. The wavelength tuning range of the device is at least 3 nm.
A 1.65μm three-section Distributed Bragg Reflective (DBR) laser for CH4 gas sensor was reported. Wide tunable range
covering R3 and R4 methane absorption line manifolds. Wavelength tunable properties and temperature stability were
characterized and analyzed. Several advantages were demonstrated compared with traditional DFB laser in harmonic