Peter A Bokhan
A V Rzhanov Institute of Semiconductor Physics, Russia
Title: Super wide luminescence and super radiance of AlxGa1-xN under optical and e-beam pumping
Biography
Biography: Peter A Bokhan
Abstract
It is desirable for the ultrafast communications, optical computer, etc., to create the lasing medium with as broad band as possible. To solve this task, the investigations of lasing and luminescence characteristics Si doped AlxGa1-xN epitaxial films 0.5…1.2 µm thickness on the sapphire substrate were carried out. The following excitation methods were used: а) by an electron beam with the energy to 20 keV, pulse duration 10 …100 ns; b) second harmonics and summary frequency of copper vapor laser on wave length 255, 271 and 293 nm; c) fourth harmonic of Nd3+:YAG laser with wave length 266 nm. In either case, the luminescence spectra are similar and they have an edge band with x-dependent wavelength from 365 nm to 310 nm and a broad band taking over the whole visible spectral range and near infrared one with broad band up to 500 THz. The main characteristics of superradiance in the broad band are presented. The spectral range depends from x and extends from 400 nm to 750 nm at x=0.5 and from 330 nm to 700 nm at x=1. The gain of active media also depends from x and is equal g=70cm-1 for weak signal (0.7%/µm) for x=0.5 and g=20cm-1 for x=0.74. The dependences of output power from active media length and pumping power demonstrate three features: a smooth growth at low pumping power or at small active length, then exponential growth and eventually comes to the saturation. The obtained resultants can be used for both the creation of waveguide lasers in a wide range and lasers with the femtosecond pulse duration.