Yasuyoshi Uchida

Compact and Low-Loss Coherent Mixer Based on High Δ ZrO 2 -SiO 2 PLC

In this paper, we report design and characteristics of a compact coherent mixer based on high Δ planar lightwave circuit (PLC) which consists of ZrO₂-doped silica glass. The PLC with 5% or more Δ is realized by employing ZrO₂ as a dopant. Propagation loss of the fabricated 5.5%-Δ ZrO₂-SiO₂ PLC is reduced to 0.02 dB/cm by an optimized fabrication process. A coherent mixer is designed and fabricated by using ZrO₂-SiO₂ PLC and size of the mixer chip is reduced to 4 mm × 2 mm. Coupling loss between standard single-mode fiber and ZrO₂-SiO₂ PLC is reduced to less than 0.31 dB/facet by an optimized spot-size converter.

Low loss 1×93 wavelength selective switch using PLC-based spot size converter

A massive port count WSS using planar lightwave circuit as optical input/output ports is proposed. We demonstrate a 1×93 LCOS-based WSS with less than 9.0 dB insertion loss and typically 37.0 GHz 0.5 dB passband width.

Compact and Low-Loss ZrO 2 -SiO 2 PLC-Based 8 × 8 Multicast Switch for CDC-ROADM Application

We report a compact 30×9mm² 8×8 multicast switch based on a ZrO₂-SiO₂ PLC. Low insertion loss of 12.8dB including coupling loss to SMF, low crosstalk less than -50dB, and low polarization dependent loss of 0.5dB are achieved.

Ultra-Compact 8-Arrayed 8×1 Switch Consists of ZrO 2 -SiO 2 -Based High Δ PLC

We report an ultra-compact 21mm × 9mm 8-arrayed 8×1 switch based on the ZrO₂-SiO₂ PLC. Low insertion loss of less than 3.2dB in C-band was achieved by low loss coupling technique using a high-Δ fiber.

Compact and low-loss ZrO 2 -SiO 2 PLC-based 8×8 multicast switch for CDC-ROADM application

In this paper, we report design and characteristics of a compact and low-loss multicast switch (MCS) based on a high Δ planar lightwave circuit (PLC) which consists of ZrO₂ doped silica glass. Chip size of an 8 × 8 MCS consists of an eight-arrayed 1 × 8 splitter and an eight-arrayed 8 × 1 switch is reduced to 30 mm × 9 mm by using the ZrO₂-SiO₂ PLC with 5.5%-Δ. Eight-input and eight-output ports of the MCS are arrayed at the one side of the chip, and coupled to optical fibers with a 16-fiber V-groove array. A high Δ fiber is used to reduce coupling loss to the ZrO₂-SiO₂ PLC, and the high Δ fiber is spliced to a single-mode fiber (SMF) by using low-loss splicing technique. Coupling loss between the ZrO₂-SiO₂ PLC and the SMF is reduced to 0.4 dB/facet. Average insertion loss of the fabricated MCS is 12.8 dB including coupling loss to the SMF. Extinction ratio and polarization dependent loss of the MCS are over 50 dB and less than 0.5 dB in L-band, respectively.

Vertical Spot Size Converter with 0.06dB/facet coupling loss using 2.5%Δ silica-based waveguide

A vertical Spot Size Converter (SSC) with vertically tapered structure was made by using Plasma Enhanced Chemical Vapor Deposition (PECVD) and a shadow mask. With the vertical SSC, a coupling loss between 2.5%Δ waveguide and a single mode fiber (SMF) was decreased to 0.06dB/facet, drastically.