Multi-photon excitation is a well-established tool for three-dimensional imaging that is now widely used in life sciences, particularly in the field of neuroscience. An ultrafast (usually femtosecond) laser is focused to a small beam waist. The high peak intensity at this location, and only this location, is able to drive two-photon excitation of fluorescent dyes, proteins, and endogenous materials. By scanning this laser spot in xyz, a two-dimensional image slice or three-dimensional image cube can be built up with high signal-to-noise ratio and minimal thermal impact on live tissue.
Such ultra-short pulses of below 250 fs can be produced only by operating a laser in the mode-locked regime. These lasers operate mostly at a fixed repetition rate of 40 to 100 MHz, which is well suited for most imaging applications. The exact repetition rate is given by the individual laser oscillator. The common approach is to adapt the positioning system (scanner) to the exact laser frequency.
A repetition rate tunable source would allow the matching of the lasers to a reference frequency. This would ease the imaging process. But it also allows the synchronization of the source to a second source (e.g. at a different wavelength). This would enable techniques like time-division multiplexing between separate laser sources, pump probe experiments or asynchronous optical sampling techniques to be used in multi-photon imaging applications.
Coherent offers a wide range of mode-locked lasers for nonlinear imaging. The project is centred around the development of a repetition rate adjustable source, which can be locked to external reference frequencies, as a base for novel 2p laser sources. The project spans from concept evaluation over optical laser development and electronic signal stabilization to implementation into concept demonstrators.
At Coherent, we believe that diversity, equity, and inclusion (DE&I) are the cornerstones of a thriving organization. We are committed to creating a workplace where everyone feels empowered, valued, and respected, regardless of their background, identity, or experiences. Please find our global policies here: Diversity & Inclusion | Coherent
In Coherent Scotland we offer flexible working hours with opportunity to shift the working day around core hours. Hours can be accumulated to allow a short working day on a Friday.
CDT Essential Criteria
A Masters level degree (MEng, MPhys, MSc) at 2.1 or equivalent.
Desire to work collegiately, be involved in outreach, undertake taught and professional skills study.
Project Essential Criteria
Project Desirable Criteria
Self-starter capable of looking for answers and happy to engage colleagues to build their knowledge base.
The CDT in Applied Photonics provides a supportive, collaborative environment which values inclusivity and is committed to creating and sustaining a positive and supportive environment for all our applicants, students, and staff. For further information, please see our ED&I statement: https://bit.ly/3gXrcwg.
Forming a supportive cohort is an important part of the programme and our students take part in various professional skills workshops, including Responsible Research and Innovation, and attend outreach training.