About Us

Caledonian Photonics Limited is a consultancy in the field of robust, miniaturised solid-state lasers and associated optical systems. We have expertise in design for manufacture, reliability and environmental insensitivity, with experience of the academic, scientific and defence markets. Based in central Scotland, Caledonian Photonics was founded in May 2018. Since that time Caledonian Photonics has been engaged in consultancy to the Photonics industry and in technology development for exploitation in future laser products.

Caledonian Photonics is a member of Technology Scotland and Photonics Scotland.

Founder & CEO

Dr Stephen T Lee

Stephen Lee, Caledonian Photonics’ founder and CEO, has 23 years of experience in the design and manufacture of solid-state lasers and their integration into optical systems. Stephen’s PhD from the University of Strathclyde in experimental laser physics concentrated on increasing the stability and practicality of ultrashort-pulsed diode-pumped solid-state laser systems. He further developed this area of expertise during his 6 years at Coherent as a senior laser design engineer engaged in new product design and introduction of Ti:Sapphire lasers for bioscience applications. Stephen then spent 10 years at Thales UK developing robust lasers for harsh environments where he held the positions of Thales UK Laser Expert, Engineering Manager and Design Authority for the Defence Lasers product line. Stephen is a Chartered Physicist, a Fellow of the Institute of Physics, and is an inventor of 5 granted patents in the field of environmentally-robust lasers.



Caledonian Photonics is active in consultancy to the Photonics industry, where we offer:

  • Domain knowledge of defence, scientific and commercial photonics applications, including within Quantum Technologies
  • Photonics system architecting
  • Laser resonator and optical system design using Zemax and SOLIDWORKS
  • Feasibility studies and prototyping in Caledonian Photonics’ lab
  • Design for manufacture, reliability and environmental insensitivity
  • Grant proposal writing with recent successful experience of Innovate UK and the UK Defence and Security Accelerator



Development Projects

Caledonian Photonics is currently engaged in several technology-development and product-development projects. Some examples are shown below.


QT Assemble brings together a consortium of UK companies to develop highly-innovative assembly and integration processes for new markets in quantum technologies. Waveguide writing, nanoscale alignment and monolithic integration will be used to deliver new levels of performance in robust and reliable platforms. High-performance components and systems will be demonstrated including highly-integrated lases, photon sources, photon detectors and ultra-cold matter systems. New commercial opportunities have been identified that require reliable and robust operation in quantum sensing and quantum information processing markets.

QT-Assemble is a 36-month, Innovate UK-Funded Quantum Technologies project that started on September 1st 2020. The project brings together a consortium of 14 companies and universities, led by Fraunhofer UK Research.


Navigation using space-based satellite signals underlies many critical technologies across the UK. Most advanced navigation technologies rely on the signals from networks known as the Global Navigation Satellite System (GNSS) to remain accurate over long distances. Loss of these signals result in an unstable navigation systems and increasingly less accurate location and direction estimation during operation.

GNSS signals may be lost accidentally from criminal activity or due to military action. For example, in 2018 several passenger flights off the Norwegian coast lost GNSS signals due to signal ‘jamming’ from military exercises. In addition, ‘Spoofing’ or deliberately transmitting false guidance signals has been demonstrated as an insidious cyberweapon that can deliberately mislead and fool cargo or passenger vessels. As systems are increasingly automated, the consequences of the loss of GNSS signals dramatically increase and may include loss of property, or in the extreme case, loss of life. Local on-board instruments can provide measurements to stabilise current navigation system technology without GNSS signals. Quantum technology-based sensors have the potential to provide stability to navigation systems over long periods of time due to the unique combination of high sensitivity to motion with superb isolation from changes in the surrounding environment. High-BIAS2 will demonstrate the ability of a quantum rotation sensor’s ability to stabilise the orientation of aircraft guidance system in the absence of GNSS signals. Local stabilisation using quantum technology will decrease the reliance of navigation systems on GNSS and provides a measure of protection against signal loss, jamming, and spoofing to increase safety and security.

High-BIAS2 is a 36-month, Innovate UK-Funded Quantum Technologies project that started on August 1st 2020. The project brings together a consortium of 7 companies, led by Cold Quanta UK.


Progress in commercializing cold-atom-based quantum instruments is limited by the availability of reliable size, weight, power and cost-reduced narrow linewidth lasers. Great progress has been made in the development of semiconductor laser platforms to allow for many of the laser-cooling functions to be achieved, but some of the more-challenging functional requirements are unlikely to be met by this approach. The Safire project will accelerate the commercialisation of cold-atom Quantum technologies including optical clocks, gravimeters, inertial-navigation units and ion-trap quantum computers.

In optical clocks, the magic wavelengths for the creation of an optical lattice at 813 nm (Sr) and 759 nm (Yb) require high power and narrow linewidth. This function is generally achieved with a tunable Ti:Sapphire laser. These laser systems generally cost ~£100k and are large and fragile devices, making them one of the primary impediments to system miniaturisation and cost-reduction.

Many quantum instruments based upon cold-atom interferometry, such as gravimeters and inertial navigation units for GNSS-free navigation, require a narrow-linewidth Raman-beam to operate. In Rubidium interferometers the relatively high-power (multiple Watts in some systems) and narrow linewidths (~10s of kHz) required are often provided by a frequency-doubled telecoms-fibre laser. These lasers are expensive (\>£50k) and their complexity often leads to unreliable operation. This represents a significant risk to the potential commercialisation of interferometer-based instruments that must be fielded in non-laboratory environments.

The Safire project will develop a new capability in ultra-compact diode-pumped-solid-state lasers that addresses the requirements of the optical lattice function in clocks, the Raman-beam function in atom interferometers, and also for ion-trap quantum computers, in a form-factor appropriate for integration into robust Quantum instruments usable outside of the laboratory environment. This development builds upon NPL’s long history in optical clock development, Optocap and RAL-Space’s experience in micro-ECDLs for cold-Rubidium instruments from the Innovate REMOTE project, and on Caledonian Photonics’ capability in miniaturised, robust monolithic DPSS lasers.

Safire is an 18-month, Innovate UK-Funded Quantum Technologies project that started on April 1st2020. The project brings together a consortium of 4 companies, led by Caledonian Photonics.