Wavelength Tuning Limitations in Optically Pumped Type-II Antimonide Lasers
Journal Article (Postprint)
AIR FORCE RESEARCH LAB KIRTLAND AFB NM
Pagination or Media Count:
In this paper, we examine the wavelength tuning limitations of type-II antimonide lasers containing InAsInGaSbInAs quantum wells. Wavelength tuning is accomplished by varying the thickness of the InAs electron wells while keeping all else fixed. In principle, these wells can be tuned from lambda approximately equal 2.5 m out to far IR wavelengths by increasing the thickness of the InAs layers. However, a practical upper limit of lambda approximately equal 9.5 micronmeters is set due to the high waveguide losses awg and the diminishing modal overlap with the gain at longer wavelengths. The waveguide losses grow as awg varies as lambda 3.44 and are attributable to free carrier absorbance. In order for the long-IR laser devices to achieve threshold, they must continually band fill, spectrally tuning to shorter wavelengths, until the laser gain exceeds the losses, which occurs near 9.5 micronmeters.
- Inorganic Chemistry
- Lasers and Masers