A small divergence angle laser and its manufacturing process

Abstract

The invention discloses a laser device with a small divergence angle and a production process of the laser device. The laser device comprises a substrate as well as an active region, a first cladding and a diffraction grating layer which are sequentially arranged on the substrate, wherein one end face etching region is arranged at one end of the first cladding and one end of the diffraction grating layer; the bottom of the end face etching region is positioned in the substrate; a divergence angle improving layer is arranged in the end face etching region; the diffraction grating layer and the divergence angle improving layer are sequentially coated with a second cladding, a contact layer and a p-metal electrode layer; an n-metal electrode layer is plated on the lower surface of the substrate; an antireflective coating layer is plated at one end of the divergence angle improving layer; a high-reflection coating layer is plated at the other end of the divergence angle improving layer. The divergence angle is improved by improving a material for preparing a light-emitting end face accessory; an original structure of the laser device is not changed and no problem of optical waveguide morphology or coupling light control exists, so that a realization process is simple, acceptable tolerance range is wide, and the characteristics of an original laser device are not changed.

Description

technical field [0001] The invention belongs to the technical field of lasers and manufacturing techniques thereof, and in particular relates to a laser with a small divergence angle and a manufacturing technique thereof. Background technique [0002] At present, the mainstream of laser chips used in high-speed (10G, 25G, 100G rate) long-distance transmission is the design of end-face light emission. The reliability is far better than that of surface-emitting lasers (VCSEL). Generally, lasers that emit light from the normal end face such as figure 1 As shown, the light emitting surface of the laser is located on the natural cleavage plane of the laser. [0003] For end-emitting lasers, because of the asymmetric distribution of materials above and below the active region in the light-emitting plane, the asymmetry of the light field and electric field in the direction of light propagation is caused, which is manifested in the optical far-field characteristics, that is, large ...

AI Technical Summary

Problems solved by technology

In order to achieve the expected fiber coupling power, the packaging factory will put forward very high requirements on the power of the chip, and use expensive lenses to improve the coupling effect; for asymmetric light spots, it is necessary to manually adjust the coupling angle, which makes the packaging factory The packaging efficiency and cost of the package are greatly increased

[0004] In order to improve the light coupling effect, multinational companies and research institutions in various countries have tried various methods, the most important of which are two methods 1. Application of area selective growth technology (SAG) to realize the gradient distribution of the end-face active region on the vertical structure In order to improve the divergence angle; 2. Adopt a double waveguide (TWG) design, remove the upper waveguide at the light-emitting end face, and use the lower waveguide to achieve the purpose of improving the divergence angle; these solutions can make the divergence angle very small, and solve customer problems The demand for coupling efficiency, but these solutions greatly increase the complexity of the process, the manufacturing process of the chip is unstable, and there are problems that the optical axis of the beam will be skewed, which will affect the packaging production efficiency and the product yield is low.

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