Investigation of the spectral characteristics of high-pressure pulsed CO₂lasers

Abstract

Electroluminescence power profiles and 2D micropatterns have been obtained from InAsSb/InAs planar LEDs tuned at several wavelengths within the 3-5 µm band. Light confined to a small region around the top opaque contact was observed (cw mode, I > 10 mA, T = 300 K). A computer simulation showed that the reason behind the decrease of the emitting area is the current crowding that ensures non-uniform injection into the active region. The effect becomes more apparent in longer wavelength devices (emitting areas of 3.4 and 4.2 µm emitting devices are related as >10 : 1), providing direct evidence that the current crowding is affected by the bandgap energy of an active layer.

Time Resolved Pattern Evolution in a Large Aperture Laser

“…In a TEA-CO 2 laser, only one molecular transition oscillates (P20 line, Ref. [15]). In the present case, it includes a large number of axial modes simultaneously (15-20), with a free spectral range of c 2L ≃150 MHz [13].…”