Cavity length study of a resonantly pumped W-OPIC semiconductor laser
Abstract
This dissertation presents the full experimental characterization of an optically pumped mid-infrared semiconductor laser with a W-well active region and optical pumping injection cavity (W-OPIC) using pump wavelength tuning and resonant optical pumping. Particular emphasis is placed on the cavity length study of resonantly pumped devices. Four devices with different cavity lengths ranging from 312 mum to 2030 mum are cleaved from the same region of a lapped and polished semiconductor laser wafer and subsequently characterized at seven temperatures ranging from 77 K to 325 K. A fifth device with a cavity length of 399 mum is also characterized at temperatures of 77 K and 100 K. Measurements are taken for each laser separately while the resonantly pumped data for all of the lasers are analyzed as a whole for the cavity length study. The pulsed pump source is the tunable near infrared output of an optical parametric oscillator pumped by the ultra-violet third harmonic of a pulsed Nd:YAG laser, and the power of the pump beam is controlled by polarizing and attenuating optics. The spectral output is measured using a monochromating spectrometer and the output power is measured as a function of pump intensity to determine threshold pump intensity and efficiency for each device as a function of temperature and a function of pump wavelength to determine resonant pump conditions. The performance of each device is measured at resonant pump conditions, including measurements of threshold pump intensity and external differential quantum efficiency as a function of temperature and the determination of the characteristic temperature of each device. A cavity length analysis is performed to determine cavity length independent performance parameters and internal loss coefficient, which are the most appropriate parameters used to compare the performance of semiconductor lasers. When compared to the published results for other mid-infrared semiconductor lasers with W-well active regions, these devices generally compare favorably to conventional devices with W-well active regions. However, at high temperatures they perform either worse than or comparable to devices with optimized W-well active regions and other W-OPIC devices.
- Publication:
-
Ph.D. Thesis
- Pub Date:
- 2006
- Bibcode:
- 2006PhDT.......114M