Members of the Photonic Sources and Components Theme
Theme Leader: Neil Broderick
Investigators: Stephane Coen, Miro Erkintalo, Sergej Flach, Jianyong Jin, Bernd Krauskopf, Rainer Leonhardt, Stuart Murdoch, Harald Schwefel, Cather Simpson, Geoff Waterhouse
Project (SC1) New Laser Sources
Continued progress in photonics requires new sources that allow new wavelength and temporal domains to be accessed. For example, sources in the 2 to 10 micrometer range would allow the construction of new gas sensors with greatly improved accuracy since they would detect the fundamental absorptions rather than the much weaker overtones at higher frequencies. The generation of shorter optical pulses has applications ranging from laser ablation for surgery, communications, and fundamental optical science, as well as characterising physical processes.
Project (SC2) Nonlinear Propagation in Fibres and Waveguides
Fibre laser based systems are limited to a few wavelength bands, but nonlinear effects must be exploited to create new frequencies and truly broadband sources. In the past this has typically been done using nonlinear crystals resulting in bulky and expensive optical parametric oscillators (OPOs)/optical parametric amplifiers, which are limited in their tuning range by their bulk geometries which stops any attempt at dispersion engineering that would allow broader phase matching ranges (see Fig. 4). In contrast fibre based schemes are compact, highly efficient and broadly tunable.
Project (SC3) Optical Frequency Combs
An optical frequency comb comprises thousands of sharp, equally-spaced, spectral lines, each of whose optical frequency can be determined to an unprecedented level of accuracy. They have found application in areas including, all-optical clocks accurate to 1 part in 1018, ultra-sensitive multiplexed spectroscopic systems for the near and mid-IR, astronomical measurements and precision tests of the fundamental laws of nature. We aim to develop a stable frequency comb that spans the mid-IR (1.5 to 4:5 micrometer). This comb will add to the range of mid-IR sources developed in SC1 and be used by the sensors team for high precision molecular spectroscopy.
Project (SC4) New Materials, Waveguides and Components
This project will provide the new photonic materials and components necessary for other projects to succeed. We will build on our recent work on THz waveguides, along with more fundamental materials research into the optical properties of graphene and novel photonic crystals. New waveguides will also be designed for delivery of high power pulses for surgical applications (SI2). Bragg gratings and UV written waveguides will be designed and fabricated using the facilities of Photon Factory for both fundamental science (SC2) and integration into sensors (SI3). A long term ambitious goal of the photonic crystal work is to improve the energy efficiency of solar cells using a bio-mimicry approach to design super-absorbing layers.