Title :
Large-Tolerant Direct Coupling to an SMF Array With a Lens-Integrated Surface-Emitting Laser
Author :
Adachi, Koichiro ; Takei, Aki ; Suzuki, Takanori ; Tanaka, Shigehisa ; Nakanishi, Akira ; Naoe, Kazuhiko
Author_Institution :
Central Res. Lab., Hitachi, Ltd., Tokyo, Japan
Abstract :
As a solution to provide a small-size and low-cost 100-Gb/s optical module, direct optical coupling between a lens-integrated surface-emitting DFB laser (LISEL) array and a single-mode fiber (SMF) array is demonstrated. A very-small far-field angle (~2°) was obtained by monolithic integration of an InP lens with a laser chip. As a result, each channel of the LISEL array can directly couple to an SMF without any additional external optical components. The measured misalignment tolerance between the LISEL array and an SMF array was sufficiently large, namely, ±5.5 μm, at excess loss of 1 dB over all four channels with the maximum coupling efficiency of 8.4 dB. These measurement results are in good agreement with a theoretical calculation based on Gaussian optics. These results demonstrate that high coupling efficiency (-3 dB) can be achieved while large misalignment tolerance (±4.5 μm) at excess loss of only 1 dB is maintained.
Keywords :
III-V semiconductors; distributed feedback lasers; indium compounds; integrated optoelectronics; lenses; optical fibre couplers; optical fibre losses; optical fibre testing; semiconductor laser arrays; surface emitting lasers; Gaussian optics; InP; external optical components; indium phosphide lens; large-tolerant direct coupling; laser chip; lens-integrated single-mode fiber array; lens-integrated surface-emitting DFB laser array; misalignment tolerance measurement; monolithic integration; optical loss; Arrays; Couplings; Fiber lasers; Lenses; Loss measurement; Optical coupling; Surface emitting lasers; Surface-emitting laser; integrated optics; optical interconnects;
Journal_Title :
Photonics Technology Letters, IEEE
DOI :
10.1109/LPT.2015.2399922