Objectives

Outcome:

Lithium tantalate‐based photonic integrated circuits (PICs) that integrate low-loss optical routing, high electro‐optic modulation efficiency, and soliton microcomb generation for broadband telecommunications and high-power applications.

Objective structures:

A planar integrated platform featuring microresonators and waveguide-based electro‐optic modulators with low birefringence and high-density arrangement.

Objective properties:

Low optical loss, high electro‐optic efficiency (VπL = 1.9 Vcm), broad operational bandwidth (up to 40 GHz and covering telecommunication bands), enhanced chemical and mechanical stability, and reduced birefringence.

Key metrics:

  • Electro-optic modulation efficiency (VπL): 1.9 Vcm
  • Electro-optic bandwidth: 40 GHz
  • Optical propagation loss: 5.6 dB/m
  • Soliton repetition rate: 30.1 GHz and 81 GHz
  • Soliton spectral bandwidth: 4.0 THz and 4.9 THz
  • Soliton pulse duration: 71 fs and 63 fs
  • Microwave phase noise: -86 dBc/Hz at 10 kHz; -114 dBc/Hz at 1 MHz

Procedures

LTOI Wafer Fabrication
Hydrogen Ion Implantation
Equipment:
  • x-cut bulk LiTaO3 wafer
  • Ion implanter
Wafer Bonding
Equipment:
  • Blank high-resistivity silicon wafer
  • Thermal silicon dioxide layer
Thermal Annealing & Exfoliation
Equipment:
  • Annealing furnace
Edge Removal & Chemical Mechanical Polishing
Equipment:
  • Edge removal tools
  • Chemical mechanical polishing (CMP) equipment
LiTaO PIC Fabrication
Hard Mask Deposition
Equipment:
  • PECVD system
Photolithography Patterning
Equipment:
  • DUV stepper photolithography system
Pattern Transfer via Dry Etching
Equipment:
  • Reactive ion etcher
Device Layer Etch
Equipment:
  • Ion Beam Etcher (IBE)
Redeposition Removal
Equipment:
Thermal Annealing
Equipment:
  • Annealing furnace
Upper Cladding Deposition
Equipment:
  • PECVD system
Chip Release
Equipment:
  • Dry etching system
  • Bosch process equipment
  • Backside wafer grinder
DUV Stepper-Compatible Lift-Off for Metal Electrodes
SiO Layer Deposition
Equipment:
  • PECVD system
Pattern Definition
Equipment:
  • DUV stepper lithography system
Undercut Sacrificial Layer
Equipment:
Metal Deposition & Lift-Off
Equipment:
  • Metal deposition system
  • Photoresist lift-off setup
SiO Layer Removal (Optional)
Equipment:
Optical and Electrical Characterization Measurements
CW Laser Resonance Locking
Equipment:
  • ECDL
  • Pound-Drever-Hall locking system
  • Wavemeter
  • Input lensed fibre
Transmission Curve Measurement
Equipment:
  • Frequency comb
  • Transmission measurement system
Electro-Optic Tuning
Equipment:
  • ECDL
  • Fiber polarization controller
  • Oscilloscope
  • MZM modulator
High-Speed Bandwidth Measurement
Equipment:
  • High-speed microwave probes
  • 50 Ω load
  • Tapered lensed fibres
  • Erbium-doped fibre amplifier (EDFA)
  • Bandpass filter
  • 50 GHz photodiode
Soliton Initiation via Single-Sideband Tuning
Equipment:
  • ECDL
  • Erbium-doped fibre amplifier (EDFA)
Raman Measurement
Raman Characterization
Equipment:
  • Confocal RM5 Raman microscope