Narrow Linewidth Vertical Cavity Surface Emitting Semiconductor Laser Based on Lateral Grating

Abstract

A vertical-cavity surface-emitting semiconductor laser is disclosed. The vertical-cavity surface-emitting semiconductor laser comprises: a highly doped substrate; the resonant cavity which is positioned on the front surface of the highly-doped substrate and is used for selecting a mode and expanding the cavity length; a lateral optical grating which surrounds the resonant cavity and is used for carrying out diffraction feedback on light leaked to the lateral optical grating from the active region of the resonant cavity so as to narrow the line width; a contact layer located on the lateral grating; and metal electrodes including a bottom metal electrode and a top metal electrode, wherein the bottom metal electrode is located on the back of the highly doped substrate, and the top metal electrode is located on the contact layer. The laser is simple in structure, small in size, low in preparation cost, low in power consumption and narrower in laser line width.

Description

technical field [0001] The invention relates to the technical field of semiconductor lasers, in particular to a vertical cavity surface-emitting semiconductor laser with extended cavity length and narrow line width based on a lateral grating. Background technique [0002] Narrow linewidth vertical cavity surface emitting lasers are widely used in coherent communication, sensing, spectroscopy and precision measurement and other technical fields. With the continuous advancement of science and technology, people have increasingly stringent requirements on the performance of core light sources. For example, atomic clocks used in navigation systems must require light sources to have narrower linewidths (1-10MHz) in order to be compatible with natural atomic linewidths (such as Cesium atom is 5MHz) compatible, thereby reducing the noise floor of the sensor to improve the performance of the sensing system. Most laser cooling and trapping experiments use external cavity diode laser...

AI Technical Summary

Problems solved by technology

The effective cavity length of the traditional VCSEL is very short, only about one wavelength, while the extended cavity length can be 2-3 wavelengths long, due to the cold cavity length Δυ c =Tc / n g 2L c , so extending the effective cavity length of the resonant cavity can reduce the linewidth of the cold cavity, and then by the revised Shaw-Town linewidth formula Δυ ST =(hυ / P 0 )(πn sp n 0 )(Δυ c ) 2 It can be seen that reducing the linewidth of the cold cavity can narrow the laser linewidth caused by spontaneous emission, and the traditional VCSEL only uses the upper and lower DBRs to select the specific wavelength of light

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