title: A terahertz system using semi-large emitters: noise and performance characteristics.
abstract: We have built a relatively simple, highly efficient, terahertz (THz) emission and detection system centred around a 15 fs Ti:sapphire laser. In the system, 200 mW of laser power is focused on a 120 microm diameter spot between two silverpaint electrodes on the surface of a semi-insulating GaAs crystal, kept at a temperature near 300 K, biased with a 50 kHz, +/- 400 V square wave. Using rapid delay scanning and lock-in detection at 50 kHz, we obtain probe laser quantum-noise limited signals using a standard electro-optic detection scheme with a 1 mm thick (110) oriented ZnTe crystal. The maximum THz-induced differential signal that we observe is deltaP/P = 7 x 10(-3), corresponding to a THz peak amplitude of 95 V cm(-1). The THz average power was measured to be about 40 microW, to our knowledge the highest power reported so far generated with Ti:sapphire oscillators as a pump source. The system uses off-the-shelf electronics and requires no microfabrication techniques.
authors.affiliation: Department of Applied Physics, Faculty of Applied Sciences, Delft University of Technology, Lorentzweg 1, 2628 CJ Delft, The Netherlands.
authors.forename: G
authors.initials: G
authors.lastname: Zhao
authors.forename: R N
authors.initials: RN
authors.lastname: Schouten
authors.forename: N
authors.initials: N
authors.lastname: van der Valk
authors.forename: W Th
authors.initials: WT
authors.lastname: Wenckebach
authors.forename: P C M
authors.initials: PC
authors.lastname: Planken
mesh_terms: D001152:Arsenicals / Q000737:chemistry*; D003460:Crystallization / Q000379:methods*; D003461:Crystallography / Q000379:methods; D055590:Electromagnetic Phenomena / Q000295:instrumentation*; D004867:Equipment Design; D019544:Equipment Failure Analysis; D005708:Gallium / Q000737:chemistry*; D007834:Lasers; D008422:Materials Testing; D008872:Microwaves; D055095:Optics and Photonics / Q000295:instrumentation; D010775:Photic Stimulation / Q000295:instrumentation / Q000379:methods; D011786:Quality Control; D012666:Semiconductors; D012680:Sensitivity and Specificity; D013057:Spectrum Analysis / Q000295:instrumentation* / Q000379:methods; D013269:Stochastic Processes; D013691:Tellurium / Q000737:chemistry; D014159:Transducers; D017967:Zinc Compounds / Q000737:chemistry
chemical_list: D001152:Arsenicals; D017967:Zinc Compounds; C043055:gallium arsenide; D005708:Gallium; D013691:Tellurium