A kind of semiconductor laser and its manufacturing method

Abstract

The invention discloses a semiconductor laser and a manufacturing method thereof. The semiconductor laser integrates the first waveguide layer and the second waveguide layer in the passive area by butt-growing in a resonant cavity, and injects current into the active area to generate optical gain. When the lasing is output, it will pass through the double-layer waveguide in the passive area, so that when the light field is coupled to the lower waveguide and reaches the output end face, the vertical size of the spot is effectively increased, the near-field spot is expanded, and the far-field divergence angle is reduced. Therefore, the output quality of the light beam is improved, the adjustment of the light beam is beneficial, the coupling efficiency of the optical fiber is improved, and the coupling cost of packaging is reduced. At the same time, when the light field is transmitted from the double-layer waveguide in the passive area to the single-layer waveguide in the active area, the loss will increase compared with the use of only a single-layer waveguide, thereby increasing the loss of external feedback light, thereby improving the laser’s resistance. reflexes.

Description

technical field [0001] The invention relates to the field of semiconductor light-emitting devices, in particular to a semiconductor laser and a manufacturing method thereof. Background technique [0002] Semiconductor lasers have been widely used in optical fiber communications, pump sources, material processing, optical sensing, lidar and other fields due to their small size, light weight, high electro-optical conversion efficiency, stable performance, high reliability and long life. . However, since the active region of the semiconductor laser generally adopts a multi-quantum well structure, its thickness is in the range of 100~200nm and the width is in the range of 2~5μm, the refractive index distribution of the light-emitting end face is not symmetrical, resulting in its far-field characteristics showing an asymmetric ellipse Light spot, especially in the vertical direction, due to its thin thickness, the far-field divergence angle in the vertical direction is generally...

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Problems solved by technology

However, since the active region of a semiconductor laser generally adopts a multi-quantum well structure, its thickness is in the range of 100-200nm, and its width is in the range of 2-5μm. The light spot, especially in the vertical direction, due to its thin thickness, the far-field divergence angle in the vertical direction is generally 40~60°, which is much larger than the divergence angle in the horizontal direction, which is not conducive to the adjustment of the beam, reduces the coupling efficiency of the fiber, and affects the semiconductor use of lasers

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