title: Photodetector based on Vernier-Enhanced Fabry-Perot Interferometers with a Photo-Thermal Coating.
abstract: We present a new type of fiber-coupled photodetector with a thermal-based optical sensor head, which enables it to operate even in the presence of strong electro-magnetic interference and in electrically sensitive environments. The optical sensor head consists of three cascaded Fabry-Perot interferometers. The end-face surface is coated with copper-oxide micro-particles embedded in hydrogel, which is a new photo-thermal coating that can be readily coated on many different surfaces. Under irradiation, photons are absorbed by the photo-thermal coating, and are converted into heat, changing the optical path length of the probing light and induces a resonant wavelength shift. For white-light irradiation, the photodetector exhibits a power sensitivity of 760 pm/mW, a power detection limit of 16.4 μW (i.e. specific detectivity of 2.2 × 105cm.√Hz/W), and an optical damage threshold of ~100 mW or ~800 mW/cm2. The response and recovery times are 3.0 s (~90% of change within 100 ms) and 16.0 s respectively.
authors.affiliation: Laser Physics and Photonic Devices Laboratories, School of Engineering, University of South Australia, Mawson Lakes, South Australia 5095, Australia.
authors.forename: George Y
authors.initials: GY
authors.lastname: Chen
authors.affiliation: Future Industries Institute, University of South Australia, Mawson Lakes, South Australia 5095, Australia.
authors.forename: Xuan
authors.initials: X
authors.lastname: Wu
authors.affiliation: Future Industries Institute, University of South Australia, Mawson Lakes, South Australia 5095, Australia.
authors.forename: Xiaokong
authors.initials: X
authors.lastname: Liu
authors.affiliation: Laser Physics and Photonic Devices Laboratories, School of Engineering, University of South Australia, Mawson Lakes, South Australia 5095, Australia.
authors.forename: David G
authors.initials: DG
authors.lastname: Lancaster
authors.affiliation: Laser Physics and Photonic Devices Laboratories, School of Engineering, University of South Australia, Mawson Lakes, South Australia 5095, Australia.
authors.forename: Tanya M
authors.initials: TM
authors.lastname: Monro
authors.affiliation: Future Industries Institute, University of South Australia, Mawson Lakes, South Australia 5095, Australia.
authors.forename: Haolan
authors.initials: H
authors.lastname: Xu