Semiconductor lasers spectral linewidth

The spectral linewidth of standard Fabiy-Perot semiconductor lasers is typically on the order of 100 MHz. For matty applications, such as holography, spectroscopy. 

H. Sato and T. Fujita, Spectral linewidth broadening due to selfmodulation of the refractive index of semiconductor lasers, Appl. 

J. Harrison and A. Mooradlan "Spectral Linewidth of Semiconductor Lasers" Fritz Haber International Symposium on Methods of Laser Spectroscopy, Dec. I6 - 20, (1985). 

The basic principle of semiconductor lasers [5.113-5.117] may be summarized as follows. When an electric current is sent in the forward direction through a p-n semiconductor diode, the electrons and holes can recombine within the p-n junction and may emit the recombination energy in the form of EM radiation (Fig. 5.63). The linewidth of this spontaneous emission amounts to several cm and the wavelength is determined by the energy difference between the energy levels of electrons and holes, which is essentially determined by the band gap. The spectral range of spontaneous emission can therefore be varied within wide limits (about 0.4—40 xm) by the proper selection of the semiconductor material and its composition in binary compounds (Fig. 5.64). 

---