Tapered Photonic Crystal Laser Based on Photonic Crystal Defect State Mode Control

Abstract

The invention discloses a tapered photonic crystal laser based on photonic crystal defect state mode control, comprising: an epitaxial layer structure, the epitaxial layer structure includes: an N-type substrate; an N-type confinement layer located on the N-type substrate On the perfect one-dimensional photonic crystal, located on the N-type confinement layer; active region, located on the perfect one-dimensional photonic crystal; P-type confinement layer, located on the active region; P-type contact layer, located on the P-type confinement layer layer; and a tapered structure, arranged on the P surface of the epitaxial layer, the tapered structure includes: a ridge waveguide part; The photonic crystal also contains a defect layer that breaks the periodicity of the perfect one-dimensional photonic crystal, and the active region is located in the defect layer. The laser can improve the beam quality of the semiconductor laser, increase the output power, reduce the divergence angle in the vertical direction, and realize stable vertical mode output.

Description

technical field [0001] The disclosure belongs to the field of semiconductor lasers, and relates to a tapered photonic crystal laser based on photonic crystal defect state mode control. Background technique [0002] Semiconductor lasers have many advantages such as light weight, small size, and easy integration, and can also achieve high-power and high-efficiency output. At present, semiconductor lasers are used in many fields such as material processing, communication, military affairs, and medical treatment. However, in these applications, including pumping sources for solid-state and fiber lasers, laser scalpels, laser weapons, metal cutting and welding, laser displays, etc., there are high requirements for the brightness of lasers. The realization of high brightness needs to obtain high output power and high beam quality at the same time. Traditional wide-contact semiconductor lasers can obtain high single-tube output power and power conversion efficiency, but due to th...

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Problems solved by technology

However, these structures can only reduce the divergence angle to a certain extent, and the minimum full-width half-maximum divergence angle can be obtained below 20°, and cannot further reduce the divergence angle to less than 10°

On the other hand, the ratio of confinement factors between the fundamental mode and higher-order modes of these mode-extended structures is not large enough, and it is easy to cause lasing of higher-order modes in the vertical direction under high current.

In addition, the refractive index in the vertical direction may change due to local temperature differences, resulting in changes in the mode distribution

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