The core light-emitting part of a semiconductor laser is a pn junction die composed of p-type and n-type semiconductors.
Release time:
2021-11-12
Source:
Source
This mainly depends on the quality of the semiconductor material, the die structure and geometry, the internal structure of the package and the encapsulation material, the application requires to improve the internal and external quantum efficiency of the semiconductor laser. The conventional Φ5mm semiconductor laser package is to bond or sinter a square die with a side length of 0.25mm on the lead frame.
The core light emitting part of the semiconductor laser is a pn junction die composed of p-type and n-type semiconductors. When the minority carriers injected into the pn junction recombine with the majority carriers, it will emit visible light, ultraviolet light or near infrared light. However, the photons emitted by the pn junction are non-directional, that is, they have the same probability of being emitted in all directions, so that,
Not all the light generated by the die can be released, which mainly depends on the quality of the semiconductor material, the structure and geometry of the die, the internal structure of the package and the encapsulation material, and the application requires to improve the internal and external quantum efficiency of the semiconductor laser. The conventional Φ5mm semiconductor laser package is to bond or sinter a square die with a side length of 0.25mm on a lead frame. The positive electrode of the die is connected to a gold wire through a spherical contact point. The bonding is that the inner lead is connected to one pin, the negative electrode is connected to another pin of the lead frame through a reflective cup, and then the top of the die is encapsulated with epoxy resin. The function of the reflector cup is to collect the light emitted from the side and interface of the die,
Emission into the desired direction angle. The epoxy resin encapsulated at the top is made into a certain shape, which has several functions: protecting the die from external corrosion; Different shapes and material properties (doped or not doped with dispersing agent) are adopted to function as a lens or a diffuse lens to control the divergence angle of light. The refractive index of the die is too related to the refractive index of air, resulting in a small critical angle of total reflection inside the die, and only a small part of the light generated by its active layer is taken out, most of it is easy to be absorbed by multiple reflections inside the die, and it is easy to cause too much light loss due to total reflection. The epoxy resin with corresponding refractive index is selected for transition to improve the light emission efficiency of the die. The epoxy resin used for constituting the tube shell must have moisture resistance, insulating properties, mechanical strength, and high refractive index and transmittance for light emitted from the die. Choosing packaging materials with different refractive indices, the effect of the packaging geometry on the photon escape efficiency is different, and the angular distribution of the luminous intensity is also related to the die structure, the light output mode, the material and shape of the packaging lens. If the pointed resin lens is used, the light can be concentrated in the axial direction of the semiconductor laser, and the corresponding angle of view is small; if the top resin lens is circular or flat, the corresponding angle of view will be increased.
Key words:
Recommended News
Beijing Xintian Technology Co., Ltd
Address: 102A, Building 27, Yard 2, Huanke Middle Road, U Valley, Liandong, Jinqiao Industrial Base, Tongzhou District, Beijing
Telephone : 0086-10-81314835/57323722
0086 182 1070 6870 (English)
WhatsAPP : 0086 182 1070 6870
Wechat ID : 0086 182 1070 6870
Fax : 86-10-57323723
E-mail : sales@xt-optic.com
Contact person : Mr.WangDi
Scan code attention to us
Copyright©Beijing Xintian Technology Co., Ltd