Module of Fiber Coupled Diode Laser Based on 808nm Single Emitter Combination

Because of the good beam quality and heat dissipation of single emitter diode laser, it is more resuitable to be used in the source of electro-optic countermeasure. Aim at the responer curve of charge-coupled device (CCD) spectrum, 808nm single emitter is used as unitsource and 24 single emitters are divided into four groups. In order to increase the output power intensity, space sombination and polarization combination are used in the experiment. Combined beam is focused in an optical fiber through the focused lens group designed by ourself. All the single emittwes are connected inseries. When the drive current is 8.5A, 162W output power is obtained from a 300um fiber core with a numerical aperture of 0.22 at 808nm and coupling efficiency of 84%.

Charge-coupled device (CCD), as a solid-state imaging device, is widely used in various optoelectronic devices, and plays an important role in reconnaissance, monitoring, and identification. The damage of CCD will cause the function of the optoelectronic device to be weakened or even lost. Therefore, the interference of strong laser on CCD has become the research focus at home and abroad. In the past, the semiconductor laser stacked array was used as the photoelectric interference light source. The beam quality of the stacked array was poor, requiring water cooling to dissipate heat, and the large system had limitations such as its application in vehicle and airborne photoelectric interference light sources. The single-tube semiconductor laser (LD) has the advantages of high beam quality and easy heat dissipation. The fiber-coupled light based on the single-tube semiconductor laser combined beam has a wide application space in photoelectric interference. Due to the high conversion efficiency and good beam quality of 976nm single-tube semiconductor lasers, the research focus of single-tube semiconductor lasers is currently focused on the 976nm band. The Fraunhofer Institute in Germany uses a step mirror reflection method to combine two single-tube semiconductor lasers with a wavelength of 975 nm into a fiber coupling module. The output power of a 105 μm fiber reaches 100 W and the coupling efficiency reaches 80%. The American company Oclaro also uses polarization beam combining technology to make a single tube semiconductor laser with a wavelength of 980 nm into a fiber coupling module. The output power of 105 μm fiber is 100 W and the coupling efficiency is 73%. Multiple fiber coupling modules are bundled by a fiber combiner, and the power can reach thousands of watts. The single-tube semiconductor laser beam combining technology with a wavelength of 808nm is relatively lagging. At present, there are no reports in the literature. From the CCD spectral response curve used in the photoelectric interference experiment, the response range of the silicon CCD is 200 ~ 1100nm. At the same irradiance, the spectral responsivity at the wavelength of 976nm is only about 40% at 808nm. Obviously, in order to improve the interference efficiency to the CCD device, it is an effective way to apply the 808nm semiconductor laser to the photoelectric interference light source. In this paper, 24 8W single-tube semiconductor lasers are divided into 4 groups, 6 in each group. Through fast and slow axis collimation, spatial beam combining and polarization beam combining, the beam is expanded and focused to achieve fiber-coupled output. All lasers are connected in series. Under the current excitation of 8.5A, 162W laser is output through 300μm fiber, and the coupling efficiency reaches 84%, which can be used in photoelectric interference experiments.