The Photoconductive Antenna (PCA) detector will be used in Macalester College Professor James Heyman's laboratory for ultrafast THz spectroscopy

Del Mar Photonics features customer: Professor James Heyman, Macalester College

The PCA detector will be used in Macalester College Professor James Heyman's laboratory for ultrafast THz spectroscopy. Heyman primarily studies electron dynamics in semiconductors and semiconductor heterostructures. Research is conducted with Macalester undergraduates, providing these students with important training in research techniques in Physics and Photonics. There is little barrier between research and teaching at a liberal arts college like Macalester, and Heyman's ultrafast THz lab is also used for demonstrations and instructional labs in the courses Modern Physics, Optics and Electromagnetic Theory.

PCA - Photoconductive Antenna for terahertz waves
Del Mar Photonics - PCA brochure - buy online - PCA Q&A

James Heyman
Professor of Physics and Chair
Ph.D., University of California at Berkeley, 1992

James Heyman is interested in experimental condensed matter physics and ultrafast laser spectroscopy. Students regularly collaborate with him in his NSF-funded research on ultrafast processes in semiconductors and the generation of picosecond pulses of electromagnetic radiation.

We use ultrafast optical techniques to investigate carrier transport and hot-carrier effects in semiconductors and semiconductor quantum wells. Our principle experimental technique is ultrafast THz spectroscopy, which lets us impulsively excite a material with a femtosecond optical pulse or single-cycle electromagnetic pulse, and record the resulting motion of charge in time. This allows us to investigate charge transport and observe hot-carrier phenomena in semiconductors and semiconductor heterostructures on time-scales that will be relevant to future electronic devices.

Papers (for complete list go here)

J. N. Heyman, D. Bell*, T. Khumalo*, "Terahertz Photo-Hall Measurements of Carrier Mobility in GaAs and InP". Applied Physics Letters 88 (2006): 162104.

J. N. Heyman, N. Coates* , A. Reinhardt *, and G. Strasser, "Diffusion and Drift in Terahertz Emission at GaAs Surfaces". Applied Physics Letters 83 (2003): 5476.

J. N. Heyman, P. Neocleous*, D. Hebert*, P.A. Crowell, T. Müller, K. Unterrainer, “Terahertz emission from GaAs and InAs in a Magnetic Field” Physical Review B64, (2001) 085202.

J. N. Heyman, R. Kersting, K. Unterrainer. “Time-Domain Measurement of Intersubband Oscillations in a Quantum Well” Applied Physics Letters 72 (Feb. 1998): 644-646.

J. N. Heyman, J. Barnhorst*, K. Unterrainer, J. Williams, K. Campman, P.F.Hopkins, A.C.Gossard. “Intersubband scattering of cold electrons in a coupled quantum well with subband spacing below the optical phonon energy .” Physica E 2 (1998): 195-199.

J. N. Heyman, H. Wragea, C. Linda, D. Heberta, P. Neocleousa, P.A. Crowell, T. Müllerc, K. Unterrainer. Terahertz Emission From Magneto-plasma Oscillations in Semiconductors.

Ultrafast terahertz spectroscopy can be used to probe charge and spin dynamics in semiconductors. We have studied THz emission from bulk InAs and GaAs and from GaAs/AlGaAs quantum wells as a function of magnetic field. Ultrashort pulses of THz radiation were produced at semiconductor surfaces by photoexcitation with a femtosecond Ti- Sapphire laser, and we recorded the THz emission spectrum and the integrated THz power as a function of magnetic field and temperature. In bulk samples the emitted radiation is produced by coupled cyclotron-plasma oscillations: we model THz emission from n-GaAs as magneto-plasma oscillations in a 3-D electron gas. THz emission from a modulation-doped parabolic quantum well is described in terms of coupled intersubband-cyclotron motion. A model including both 3-D plasma oscillations and a 2-D electron gas in a surface accumulation layer is required to describe THz emission from InAs in a magnetic field.
keywords: terahertz, ultrafast, InAs, GaAs, plasmon, magnetic, parabolic quantum well

Del Mar Photonics products related to ultrafast optical techniques and THZ spectroscopy:

Trestles Femtosecond Ti:Sapphire laser - Trestles 50 Manual
Trestles 20 Manual - 20/50/100 fs oscillators - FemtoStart
Trestles Finesse Ti:Sapphire oscillator - Q&A - LQ
Wedge-M Multipass Ti:Sapphire Amplifier
Amplified Ti:Sapphire System Teahupoo

Mavericks Femtosecond Cr:Forsterite laser (around 1250 nm)

Tamarack Femtosecond Er-doped fiber laser (around 1560 nm)
Buccaneer Er-doped Femtosecond OA Fiber Laser (1560nm)
Buccaneer SHG (780nm) femtosecond fiber lasers
SHG unit for femtosecond fiber lasers
Cannon Ultra-Broadband Light Source
Femtosecond Fiber Lasers from Del Mar Photonics - Er - Yb (pdf)