Spectral Characteristic Based on Fabry–Pérot Laser Diode with Two-Stage Optical Feedback
WU Jian-Wei1,2,3**, Bikash NAKARMI4
1Chongqing Key Laboratory of Optoelectronic Functional Material, Chongqing Normal University, Chongqing 400047 2State Key Laboratory of Millimeter Waves, Nanjing 210096 3College of Science, Hohai University, Nanjing 210098 4Department of Information and Communication engineering, Korea Advanced Institute of Science and Technology, Daejeon 305-714, R. Korea
Abstract:An optical device, consisting of a multi-mode Fabry–Pérot laser diode (MMFP-LD) with two-stage optical feedback, is proposed and experimentally demonstrated. The results show that the single-mode output with side-mode suppression ratio (SMSR) of ~21.7 dB is attained by using the first-stage feedback. By using the second-stage feedback, the SMSR of single-mode operation could be increased to ~28.5 dB while injection feedback power of ?29 dBm is introduced into the laser diode. In the case of up to ?29 dBm feedback power, the outcome SMSR is rapidly decayed to a very low level so that an obvious multi-mode operation in the output spectrum could be achieved at the feedback power level of ?15.5 dBm. Thus, a transition between single- and multi-mode operations could be flexibly controlled by adjusting the injected power in the second-stage feedback system. Additionally, in the case of injection locking, the outcome SMSR and output power at the locked wavelength are as high as ~50 dB and ~5.8 dBm, respectively.