Highly-Efficient Seeded Frequency Comb Generation on a Chip

Introduction

Generating new colors (frequency components) of light through nonlinear optical phenomena is one of the key drivers of modern optical technology. The spectrally diverse coherent light, widely known as an optical frequency comb, can be produced through a nonlinear process.

Applications of Optical Frequency Combs

The optical frequency comb enables:

• Energy-efficient optical communication
• Precision spectroscopy
• Optical atomic clocks

Challenges in Current Technology

However, the frequency comb sources currently rely on bulky and power-hungry laser systems, hampering their deployment outside the laboratory environment. There are great demands in lowering the size, weight, and power (SWaP) of such broadband light sources.

Despite the significant progress in the miniaturization of comb systems and microcomb technologies, it is still a huge challenge to drive a broadband (larger than an octave) comb with microwave repetition rate using on-chip pump sources due to the limited performance of on-chip lasers.

Project Goals

The COMBCHIP project aims to develop an ultra-efficient comb generator by combining:

1. The highly nonlinear AlGaAs waveguide
2. A newly developed seeded pumping scheme

Expected Outcomes

The developed comb sources will feature:

• An octave-spanning bandwidth
• Microwave repetition rate
• Ultra-low operation power

These advancements will enable chip-scale comb systems in emerging applications such as atomic optical clocks in satellites and mid-infrared spectroscopy.