Link to ResearchGate publications and downloadable papers 

Providing an integrated optics approach to laser and electro-optic systems

1. A  2.1 μm differential absorption lidar

The photo above shows a hollow waveguide integrated optic circuit for a 2.1 μm differential absorption lidar (DIAL) system. 750 micron square cross-section channels created in the dielectric substrate (in conjunction with a lid) form hollow waveguides which both confine the 2.1 μm  radiation and guide it through the circuit of integrated discrete components. The light guidance in the hollow waveguide  circuit significantly eases otherwise demanding angular alignment tolerances. As illustrated the discrete components are located in precision alignment features also formed in the surface of the substrate. The alignment features circumvent the need for complex, sensitive and expensive alignment mounts and associated time consuming and costly manual adjustment techniques. The approach has led to a compact, rugged, DIAL system, with excellent optical performance. The manufacturing approach provides the potential for quality controlled, mass production. The work was funded by CEOI-ST (the 'Centre for Earth Observation Instrumentation and Space Technology'). 

2.  A multi-wavelength mid-IR beam combiner

In collaboration with Dr Ian Elder and Prof Rob Lamb of Selex-ES, Edinburgh, a hollow waveguide integrated optic mid-IR beam combiner has been developed. As shown in the photo below, the beam combiner circuit is based on using 1.2 mm square cross-section hollow waveguides formed in a dielectric substrate to guide four different input wavelengths: 2.1 μm, 3.95 μm, 4.05 μm and 4.6 μm, to a single hollow waveguide output port. The wavelength combination process is achieved by means of three integrated dichroic components. The photo shows the circuit being assembled with one of the dichroic components located in its alignment slot. A lid forms the fourth (upper) wall of all the square section hollow waveguides. The approach has led to a compact, rugged, beam combiner with excellent optical performance and with the potential for quality controlled mass production. The work was funded by Selex-ES, Edinburgh.