Silicon Photonics

We will provide Si waveguides such as compact optical circuit, etc., depending on the customers' required design.
Advantages of NTT-AT’s Si Photonics Foundry Services
Flexibly customized Si waveguide for each customer’s requirements
- Ultra fine optical circuit achieved by the advanced nano fabrication techniques
Si waveguide circuit with low connection loss
- Spot-size converter achieving low connection loss between optical fiber and Si waveguide enables customers to evaluate the optical circuit performance precisely
Various optional services available
- Ta heater to control optical characteristics precisely
- Integration with polymer and other types of functional materials
One-stop full range of services
- From fabrication to optical characterization as well as mounting/packaging with fiber connection
Typical Si waveguide circuit design
Fabrication example
Waveguide core | 400-500nm width x 220nm height |
---|---|
Ring resonator gap | >150nm |
Waveguide area | typically 5x5mm |
Spot-size converter core | 3umx3um |
Gap between spot-size converters | >50um |
Chip size (if dicing requested) | typically 15x5.6mm |
Low connection loss based on Spot-size converter
-Typical loss: 1.5dB/connection
Structure of Spot-size converter
Fiber array connection with Si chip

Fiber array connection with Si chip
Fiber-to-chip assembly service for Silicon Photonic
Schematic of Fiber array connection

Schematic of fiber array connection
Other value added process services
- Ta heater for precise control of optical refractive index
- Hybrid combination of Si chip and functional materials such as polarization material
- Mounting structure of Laser diode chip
Ultra compact size Ta heater for precise temperature control
Applications
Functional circuits such as Optical switching, Wavelength filter
Requirement |
Precise control of Optical characteristics with localized heater |
Solutions |
1 Ta (high-melting point metal) thin layer 2 Ultra compact size heater using nano-fabrication technique 3 Locally heating by combining the low resistive Au wire |
Example of Ta heater pattern fabricated on over-cladding layer

Cross sectional veiw of a Micro heater

Ta heater pattern example

SEM image: Ta heater pattern close-up(Fig.1)
Application

Application
Introducing functional materials
Applications
Sensing devices, Ge optical detector, modulator
Requirement |
Hybrid combination of Si chip and other functional materials |
Solutions: Over-cladding layer using functional materials |
1 Partial expose of Si waveguide available 2 Damage free dry etching and wet etching process |
Fabrication example
Mounting of Laser diode chip based on high precision fabrication technique