Design Of Fiber Coupled Module Of Semiconductor Laser And It's Array

The far-field pattern of high power laser diode (LD) and its array (LDA) exhibits a relatively close resemblance to Gaussians. The cross section of the beam is elliptical. The beam divergence angle (FWHM) in the dimension perpendicular to the junction (fast axis) is about 30° ~ 40°, but in the dimension parallel to the junction axis it is 6 ~ 12 . So the beam in fast axis and in slow axis could not be collimated using a simple micro-optics. However, in most application, to obtain high quality beam, it is necessary to couple LD or LDA with fiber. Thus it is an urgent and complex technical problem.In this paper, different methods are used to couple the output radiation of high power laser diode and its array into fiber. The main contents are following:1.When couple the output radiation which from 1μ m×100μ m aperture of high power laser diode into a 50μ m multi-mode fiber by using double-curve micro-lens, we get 80% efficiency.2.When coupling the above LD with multi-mode fiber, of which the core diameter is 200 μ m, the numerical aperture (NA) is 0.22, and the refractive index is 1.61, we not only get high coupling efficiency of 88% but also imitate it with ZEMAX software.3.Using double-curve micro-lens array, we couple the output radiation from the LDA which with 19-emitter (every aperture of which is 1μm×100 μm and wavelength is 808nm,) into a LDA which with 19 fibers, and obtain efficiency of 78%. Moreover, we get 2 × 10~4 W/cm~2 light power density and 25W output light power by focusing the output light from fiber bundle into a single 400 μ m fiber.4.When couple the above LDA into fiber bundle by using 120 μm fiber as collimating lens, we get efficiency of 78%.5.At the same time, using micro-optics system , we couple the above LDA into a single 400 μm multi-mode fiber which with 0.22 NA and obtain the efficiency of 64%.