Highly efficient collective coupling between laser diode array and lensed fibre ribbon

Abstract

A new concept is proposed for lensed fibres fabricated according to a collective and low cost process. This process is based on cleaving and splicing of optical fibre ribbons and is suitable for the coupling of laser diode arrays and fibre ribbons.

Fiber array-to-photonic-chip fixation and fine tuning using laser support adjustment

“…The position of the fiber array can be controlled by means of three removable pins (7), which are connected to three external piezoelectric actuators. (b) The fine-tuning principle of the fiber array (4) after removal of the displacement pins (7) to the desired position by shrinkage of material in the tuning frames (8).…”

“…After the initial welding process, the optimal alignment can get lost due to post welding shift. We can readjust the optimal alignment by using laser trimming of the fixation frames (8). By applying laser welding-induced local heat, the arms of the frames will shrink, which can be utilized for the fine alignment of the fiber array.…”

“…Micro lenses can be assembled between cleaved fiber arrays and photodetector arrays [5], [6] or an optical micro-bench can be monolithically integrated to photodetectors [7]. A section of graded index fiber can be spliced to a single-mode fiber, which acts as a lens [8]. Otherwise, the fiber tip can be lensed to couple light in standard waveguides.…”

The approximate ABCD matrix for a parabolic lens of revolution and its application in calculating the coupling efficiency

“…However, theoretical investigations to study the coupling efficiency involve cumbersome numerical integration. Fortunately, the ABCD matrix technique can simplify the calculations of the coupling efficiency between LDs and SMFs and has been used by many researchers such as Chanclou [5,6], hyperbolic fiber lenses [7], conical lens [8], and hemispherical fiber lenses [9]. However, to the best of our knowledge, there is no such study on the parabolic lens.…”

Optical coupling method utilizing a lensed fiber integrated with a long-period fiber grating

“…For example, in the case of lensed fiber with a 50-m radius, the optical backreflection decreases from Ϫ30 to Ϫ60 dB when the working distance increases from 10 to 100 m. 11 Although it has been reported that an integrated spot size converter improves coupling, 12 the working distance is typically not more than 20 m; thus higher optical backreflections can be induced for an uncoated and cleaved fiber. Various approaches to increasing the working distance have been tried, but most working distances are still limited to less than 50 m. 13,14 Although the use of thermally expanded core fiber integrated with a coreless fiber could lead to a larger working distance, the fabrication processes with this type of fiber are relatively time consuming and complicated. 10 For example, the fabrication of a thermally expanded fiber may require 1 h at 1700°C, and three different fibers may be needed for integration.…”