Diamond has a range of extraordinary properties and the recent ability to produce high quality synthetic diamond has
paved the way for the fabrication of practical diamond devices. This paper details the recent progress in the fabrication of
waveguide structures in diamond which are desirable as the basis for quantum key distribution (QKD), quantum computing and high-power, high speed microwave chips. The diamond ridge waveguide structures are produced by photolithography and reactive ion etching (RIE) with some additional processing with a focused ion beam (FIB). The processes currently used are discussed along with experimental results. Future fabrication goals and potential methods for achieving these goals are also presented.
A fiber Bragg grating was written, using the phase mask technique, in a short length of Er<sup>3+</sup>:Yb<sup>3+</sup>-codoped fibre and its temperature and strain characteristics were investigated. Two of the three parameters of interest are associated with Bragg grating properties, namely the usual dip at the Bragg wavelength, λB, and an unexpected dip at ~2/3 λB that is the third harmonic of features within the grating having double the assumed periodicity. The third parameter is the fluorescence intensity ratio arising from a pair of transitions in Yb<sup>3+</sup> ions. This arrangement consisting of three co-located sensors offers interesting possibilities for the simultaneous measurement of three parameters.
Characterization of two simultaneous and co-located temperature-strain sensors based on FBGs and Er:Yb-codoped fiber has been performed. The sensors have demonstrated reasonable accuracies in the order of 0.4°C and 10 με over temperature and strain ranges of 20 - 150°C and 350 - 2500 με respectively.