90°-bent graded-index core polymer waveguide for a high-bandwidth-density VCSEL-based optical engine

Abstract

In this paper, we present a low-loss optical assembly utilizing a 90°-bent graded-index (GI) core polymer optical waveguide on vertical cavity surface emitting laser (VCSEL) based optical transceivers. The proposed assembly can replace conventional components such as mirrors and lenses for realizing subminiature optical engines applicable to on-board integration. To minimize the total insertion loss of the waveguide when connected to a high-speed VCSEL and a GI-core multimode fiber (MMF) at each end, the characteristics of the beam emitted from VCSELs are measured and taken into consideration for the waveguide design. In order to confirm the effect of insertion loss reduction by the waveguide numerical aperture control, 90°-bent GI-core polymer waveguides are fabricated applying the Mosquito method. The fabricated waveguide exhibits a total insertion loss as low as about 2 dB at 850-nm wavelength, which includes the coupling losses at both ends, bending, and propagation losses. We also investigate a way to reduce the insertion loss when a gap exists between the waveguide and VCSEL chip. We theoretically and experimentally confirm that filling the gap with a high index resin can reduce the coupling loss by 5 dB.

PLC-Based Integrated Refractive Index Sensor Probe with Partially Exposed Waveguide

“…In such cases, bend loss occurs in dielectric waveguides. Studies have been conducted on various high integrated optical devices to overcome bend loss, including air trenched, graded-index cores, and hybrid waveguide structures [ 18 , 19 , 20 ]. Among these methods, the difference in the RI between the core and clad can be used as a variable to control the light confinement characteristics.…”

Design Optimisation of Optical Planar Waveguide Sensor for Microplastics Detection in Water

“…Since the detection of the microplastics in water is intricate due to the aforementioned properties, a compact europium-aluminium (Eu-Al) doped polymer optical planar waveguide sensor, fabricated by using a micro-dispenser machine may be necessary to ascertain the presence of transparent and translucent microplastics in water. This is based on the fact that an optical polymer planar waveguide has superior properties [3][4][5][6], which include strong evanescent elds [7][8][9], highly exible, small and compact, and cost-effective manufacturing for large scale production especially through the Mosquito method [10][11][12][13]. Aside from that, the europium-aluminium doped polymer exhibits sharp red emission at 617 nm with high brightness and intensity [2,14,15].…”