title: Optimization of photoconducting receivers for THz spectroscopy.
abstract: We have studied the sensitivity and noise of optically gated dipole receivers made from ion implanted Si and GaAs in an optimized time domain THz spectrometer. The spectrometer uses a room temperature, dc biased, semi-insulating GaAs stripline source capable of generating up to 30 microW average power. The 10% amplitude system bandwidth for 10 microm (50 microm) dipole receivers is 3 THz (1.5 THz). A dynamic range of 4 x 10(5) Hz(-1/2) is achieved using a 10 microm dipole GaAs receiver and 2 x 10(6) Hz(-1/2) using a 50 microm dipole for a total laser power of 110 mW and THz beam power of 20 microW. The dynamic range achieved with comparable silicon receivers is a factor of 2 smaller.
authors.affiliation: Department of Physics, University of Bath, Bath BA2 7AY, UK. s.r.andrews@bath.ac.uk
authors.forename: S R
authors.initials: SR
authors.lastname: Andrews
authors.forename: A
authors.initials: A
authors.lastname: Armitage
authors.forename: P G
authors.initials: PG
authors.lastname: Huggard
authors.forename: A
authors.initials: A
authors.lastname: Hussain
mesh_terms: D004553:Electric Conductivity; D055590:Electromagnetic Phenomena / Q000295:instrumentation*; D004867:Equipment Design; D019544:Equipment Failure Analysis / Q000379:methods*; D007834:Lasers; D008872:Microwaves; D055095:Optics and Photonics / Q000295:instrumentation*; D011786:Quality Control; D012666:Semiconductors; D012680:Sensitivity and Specificity; D013057:Spectrum Analysis; D013269:Stochastic Processes; D014159:Transducers