Study Of High Power Single Longitudinal Mode Semiconductor Laser With High Order Bragg Gratings

High order Bragg gratings(HOBGs) single longitudinal-mode semiconductor laser is a new type of single longitudinal mode lasers. In order to achieve single longitudinal-mode lasing, a set of periodic refractive index perturbation is integrated into the waveguide of normal Fabry-Perot cavity laser. The HOBGs lasers have strong longitudinal-mode discrimination that operating in a stable single longitudinal mode. The multiple longitudinal-mode lasing problem of traditional edge emitting laser is solved by HOBGs lasers. Furthermore, HOBGs single longitudinal mode lasers can be integrated with other optoelectronic devices for sample preparation and stable optical property. So this new type of laser devices has wide application prospects.In this paper, HOBGs laser is designed and fabticated. The power and spectrum characteristics of HOBGs laser are tested. The main work is as follows:1) The optical properties of HOBGs coupling optical waveguide are anayzed by transmission matrix theroy and scattering theroy. And the design and calculation method of HOBGs coupling optical waveguide is obtained.2) High order Bragg gratings(HOBGs) distributed Bragg reflector(DBR) lasers at around 956 nm has been fabricated. 100 μm wide broad-stripe and 2 mm longitudinal laser cavity of HOBGs lasers are defined by i-line lithography and dry etching. Continuous-wave power of 213 m W has achieved, and having a 3 d B spectrum width of less than 40 pm at 900 m A, and operating in a stable single longitudinal mode with the side-mode suppression ratio(SMSR) of 42 d B.3) Dual-wavelength operation HOBGs distributed Bragg reflector(DBR) lasers have been fabricated with broad-stripe width of 100 μm and laser cavity length of 2 mm. Continuous-wave power of 88 m W has achieved at injection current of 1.2 A, the 3 d B spectrum linewidth of the two wavelength modes are both 40 pm. And the side mode suppression ratio(SMSR) of shorter wavelength mode and long wavelength mode are larger than 35 d B and 39 d B, respectively. The wavelength difference of two lasing modes is larger than 0.58 nm. In order to analyze the reliability of Grating coupled semiconductor lasers(GCSLs), the chips in different preparation stages and products of GCSLs are tested by Raman spectroscopy.4) High order Bragg gratings(HOBGs) distributed feedback(DFB) lasers at around 976 nm has been fabricated. 100 μm wide broad-stripe and 2 mm longitudinal laser cavity of HOBGs lasers are fabricated. Continuous-wave power of 144 m W has achieved at injection current 1.2 A, and having a 3 d B spectrum width of less than 40 pm at 1.2 A, and the side-mode suppression ratio(SMSR) of 29 d B.5) The spatial coherence properties of high power single longitudinal-mode semiconductor lasers were studied based on the theorem of partially coherent light. We firstly proposed an integral average value method(IAVM) based on the Young’s interference experiment and spatial coherence theory. Comparing with our IAVM, the largest relatively error of the traditional analysis method is 27 times larger than IAVM. And a kind of high power vertical cavity surface emitting lasers(VCSELs) triangle-arrays has been fabricated,and the spatial coherence properties of VCSELs triangle-arrays is studied.