Coupling device for semiconductor stripe laser diode (LD) and single mode fiber (SMF)

Abstract

The invention discloses a coupling device for a semiconductor stripe laser diode (LD) and a single mode fiber (SMF). The coupling device comprises the semiconductor stripe LD, a focusing telescope system, an elliptical graded index fiber (EGIF) and the SMF, wherein, the EGIF has a long axis direction and a short axis direction, the long axis direction is consistent with that of the parallel active layer of the semiconductor LD, and the short axis direction is consistent with that of the vertical active layer of the semiconductor LD. The coupling device has the advantages that the problems such as complex structure, difficulty in manufacture and the like of a lens caused by realizing efficient coupling between the LD and the SMF only by utilizing a lens system are effectively solved; and by adopting the EGIF, a light field which is coupled into the SMF after shaping transformation can also obtain efficient coupling in the event that the light field is in an incomplete circular shape.

Description

Technical field [0001] The present invention relates to the technical field of laser coupling, in particular to a coupling device of a semiconductor strip laser diode and a single-mode optical fiber. Background technique [0002] The 21st century is the era of global information integration. The advancement of optical fiber communication technology is due to the rapid development of the Internet. The coupling problem between the semiconductor laser as an important signal light source in the optical communication field and the optical fiber as the signal transmission carrier has become increasingly important. The commonly used semiconductor strip laser diode (LD) has different far-field divergence angles along the vertical active layer and parallel active layer directions due to its own structural characteristics. In the near field, the size of the light-emitting area of ​​the strip laser diode is generally within 1 μm×10 μm, the spot radius in the direction perpendicular to the a...

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Problems solved by technology

Therefore, there is a significant difference between the LD exit light field characteristics and the SMF mode field characteristics, and direct coupling will inevitably cause a large loss. Therefore, the effective coupling of the two has always been a difficult point in this field.

Due to its own structure, microlens fiber usually has the characteristics of high simplicity, easy operation, and easy packaging. However, there is an obvious defect in this solution, that is, its effective working distance is small, that is, the distance between the semiconductor laser and the microlens fiber The optimal distance between them is short (generally only a few microns), in this case the alignment of the system has a great influence on the coupling efficiency, and the tolerance is small

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