Singular Light: Integrated Single Mode Laser Converter

Singular Light: Integrated Single Mode Laser Converter, is an efficient, simple device that relies on Raman laser conversion for generating a single longitudinal mode (SLM) laser output.

The configuration offered by Singular Light not only offers a more robust generation of SLM lasers compared to conventional techniques, but it also allows ease of adjustment of the output laser frequency. These characteristics make the technology a perfect fit to answer the requirements of many areas of optical metrology and interferometry, from data storage to optical communications. With the advent of diamond quantum computing, Singular Light also presents a unique opportunity for the integration of compact laser sources on a diamond photonic chip.

Working Principle

The operation of an SLM laser is based on a single resonator longitudinal mode, meaning it emits a quasi-chromatic radiation with a rather small linewidth and low phase noise. Conventional techniques for producing an SLM laser are subject to several issues, namely mode competition, requiring complex active control loop systems and a convoluted design of optical arrangements that rely on the use of many elaborated elements within the laser cavities. This results in a SLM laser that is difficult to achieve and maintain, given its high sensitivity to external disturbances.

The working principle of Singular Light relies on the spectral compression of commercial lasers to nearly the theoretical limit. The device is integrated monolithically into a small piece of diamond which only allows one longitudinal mode of the Stokes emission to resonate, therefore generating a SLM laser output that is frequency-shifted with regard to the laser input. Diamond, with its outstanding optical and mechanical properties, allows for the direct generation of ultra-stable single-frequency light at high efficiency.

Advantages & Applications

  • Optical metrology and interferometry
  • Light detection and ranging (LIDAR)
  • High-resolution spectroscopy
  • Optical data storage
  • Optical communications
  • On-chip diamond light sources
  • Quantum computing and memory
  • Holography


  • Efficient generation of a single longitudinal mode (SLM) laser with a very small linewidth and low phase noise, already demonstrated an enhancement of 100x of peak power spectral density with > 40% average power conversion efficiency.
  • Laser output exhibits a rather long coherence length (from 10 up to 1000 metres), with a Fourier limited output of ~100 MHz linewidth.
  • Frequency-shifted laser output, with respect to the laser pump input by 30 - 50 nm, providing access to new wavelengths.
  • Ease of adjustment of the output laser frequency via length tuning of monolithic diamond resonator via angle or temperature.
  • Extremely simple optical configuration, compared to conventional methods of generating SLM lasers
  • Resilient against mode competition thanks to spectral hole burning free Raman gain technology.
  • Robust to external disturbances, thanks to complete integration of laser into a diamond host and no need for free-space optical components.
  • Single mode in both the longitudinal and transversal direction.
The technology was developed through a CERN KT Fund project (From 2019)
The IP is owned by CERN
Year Filed
Developed at
The Singular Light technology was co-developed by CERN and Macquarie University, Australia. It stemmed out of the necessity of achieving a simple, efficient and agile multi-mode to single mode converter.