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

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. 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)

Jaws Laser System Cr:Forsterite Multi-Terawatt Amplified Laser
CORTES-E-1 Table –Top Terawatt Ti:Sapphire laser
Cortes-E Femtosecond TW Laser - description
Cortes-800 40 TW 30 fs Amplified Ti:Sapphire Laser - summary
Cortes-O 200 TW Femtosecond Laser
Cortes-K Femtosecond Seed Laser for Petawatt KrF Excimer Laser
OPCPA 200TW laser

Femtosecond Autocorrelators Reef-RT (scanning)
and Reef-SS (single-shot)  - Reef-RT - buy online - specs
Autocorrelation technique - Reef-RT AA-10D manual
Avoca SPIDER Spectral Phase Measurement System - manual
Rincon Cross-Correlator Pulse Profiling Systems - TOCC
Rincon SS Single shot third-order cross-correlator
Optimization of Rincon TOAC for customer laser system

Hatteras Ultrafast Transient Absorption Spectrometer
Beacon Femtosecond Fluorescence Up-conversion Spectrometer
Femtosecond NSOM Ultrafast Near field Optical Microscope
JIBE White Light Continuum Generator
Complete Ultrafast Dynamics System - fs

Femtosecond Harmonic Generators

Kirra Faraday Optical Rotators and Isolators - models - 800nm - 1064nm - Faraday Q&A - Broadband Isolator for fs Ti:Sa laser
High Power Faraday Rotators and Isolators -FIR

Pismo Pulse Pickers: Electro-Optical Ultrafast Shutters - pdf brochure
Femtosecond Pulse Pickers Pismo Questions and Answers - 100kHz
Pismo 8-1 Manual - Pismo 8-25 Manual

4W/6W DPPS Green Laser

Pacifica Terahertz Spectrometer
Terahertz Spectroscopic Radar Mobile System for Detection of Concealed Explosives

Saturable Absorption Mirrors (SAM) - (pdf) buy online - RSAM

Photoconductive Antenna (PCA) for Terahertz Applications
PCA models - Q&A - buy online


Terahertz Spectroscopy: Principles and Applications (Optical Science and Engineering) ~ Susan L. Dexheimer

The development of new sources and methods in the terahertz spectral range has generated intense interest in terahertz spectroscopy and its application in an array of fields. Presenting state-of-the-art terahertz spectroscopic techniques, Terahertz Spectroscopy: Principles and Applications focuses on time-domain methods based on femtosecond laser sources and important recent applications in physics, materials science, chemistry, and biomedicine.
The first section of the book examines instrumentation and methods for terahertz spectroscopy. It provides a comprehensive treatment of time-domain terahertz spectroscopic measurements, including methods for the generation and detection of terahertz radiation, methods for determining optical constants from time-domain measurements, and the use of femtosecond time-resolved techniques. The last two sections explore a variety of applications of terahertz spectroscopy in physics, materials science, chemistry, and biomedicine.

With chapters contributed by leading experts in academia, industry, and research, this volume thoroughly discusses methods and applications, setting it apart from other recent books in this emerging terahertz field.

Principles of Terahertz Science and Technology (Lecture Notes in Physics) ~ Yun-Shik Lee

Principles of Terahertz Science and Technology aims to elucidate the fundamentals of THz technology and science for potential new users. It surveys major techniques of generating, detecting, and manipulating THz waves and also discusses a number of essential processes where THz waves interact with physical, chemical, and biological systems. This book serves as an introduction to THz technology for new researchers in various fields.

Many different disciplines, such as ultrafast spectroscopy, semiconductor device fabrication, bio-medical imaging and more, involve the recent development of THz technology. It is necessary to lay down a strong, common foundation among researchers, so that communication can proceed smoothly. Previous THz research activities have concentrated on generation and detection, but the focus has now shifted to practical applications of this technology, such as high-speed optoelectronic signal processing and molecular spectroscopy.

Drawing upon years of practical experience and using numerous examples and illustrative applications Yun-Shik Lee discusses:

The major techniques of generating, detecting, and manipulating THz waves
Essential processes where THz waves interact with physical, chemical, and biological systems
Medical Applications of T-Ray Imaging including, optical properties of human tissue, cancer diagnostics, reflective imaging of skin burns and detection of dental caries
Principles of Terahertz Science and Technology is an ideal book for applied physicists, microwave engineers, biomedical engineers, electrical engineers, and analytical chemists interested in the fundamentals and applications of THz engineering.

Terahertz Science And Technology For Military And Security Applications (Selected Topics in Electronics and Systems) ~ Dwight L. Woolard

The inherent advantages and potential payoffs of the terahertz (THz) regime for military and security applications serve as an important driver for interest in new THz-related science and technology. In particular, the very rapid growth in more recent years is arguably most closely linked to the potential payoffs of THz sensing and imaging (THz-S&I).
This book presents some of the leading fundamental research efforts towards the realization of practical THz-S&I capabilities for military and security applications. Relevant subjects include theoretical prediction and/or measurement of THz spectroscopic phenomenon in solid-state materials such as high explosives (e.g. HMX, PETN, RDX, TNT, etc.), carbon-fiber composites, biological agents (e.g. DNA, RNA, proteins, amino acids) and organic-semiconductor nanostructures. Individual papers also address the effective utilization of state-of-the-art THz-frequency technology in military and security relevant scenarios such as standoff S&I, screening of packages and personnel, and perimeter defense. Technical papers introduce novel devices and/or concepts that enhance THz source and detector performance, enabling completely new types of sensor functionality at THz frequency (e.g. detection at nanoscale/molecular levels), and defining new and innovative sensing modalities (e.g. remote personnel identification) for defense and security. Therefore, the collective research presented here represents a valuable source of information on the evolving field of THz-S&I for military and security applications.

  Terahertz Optoelectronics ~ Sakai, Kiyomi

The book presents recent and important developments in the field of terahertz radiation with a particular focus on pulsed terahertz radiation. Situated in the gap between electronics and optics, the terahertz frequency range of the electro-magnetic spectrum has long been neglected by scientists and engineers due to a lack of efficient and affordable terahertz sources and detectors. The advent of femtosecond lasers in the 1980s and photoconductive switches in 1984 have made the terahertz gap accessible, while at the same time advances in electronics and optics have made it narrower. Research activities in terahertz frequencies have risen dramatically since that time, funding has increased by a factor of 100 in the last decade. The reviews by leading experts are of interest to researchers and engineers as well as advanced students.

  Intense Terahertz Excitation of Semiconductors ~ S. G. Ganichev

Product DescriptionIntense Terahertz Excitation of Semiconductors presents the first comprehensive treatment of high-power terahertz applications to semiconductors and low-dimensional semiconductor structures. Terahertz properties of semiconductors are in the center of scientific activities because of the need of high-speed electronics. This research monograph bridges the gap between microwave physics and photonics. It focuses on a core topic of semiconductor physics providing a full description of the state of the art of the field.
The reader is introduced to new physical phenomena which occur in the terahertz frequency range at the transition from semi-classical physics with a classical field amplitude to the fully quantized limit with photons. The book covers a wide range of optical, optoelectronic, and nonlinear transport processes, presenting experimental results, clearly visualizing models and basic theories. Background information for future work and exhaustive references of current literature are given. A particularly valuable feature is the thorough discussion of various technical aspects of the terahertz range like the generation of high-power coherent radiation, optical components, instrumentation, and detection schemes of short intense pulses. The book complements, for the first time in form of a monograph, previous books on infrared physics which dealt with low-power optical and opto-electronic processes. It will be useful not only to scientists but also to advanced students who are interested in terahertz research.

Terahertz Frequency Detection and Identification of Materials and Objects ~ R.E. Miles

Terahertz frequency sensing has a unique part to play in the detection and identification of materials and objects. This frequency range, corresponding to a wavelength of around 0.1 mm, can be used to identify materials from their molecular spectra and to produce images of concealed objects. Terahertz spectra of drugs of abuse and explosives presented by a number of the contributing authors show that the presence of these materials can be detected in envelopes, packages and through clothing.

The technology of terahertz detection has largely been developed around expensive and bulky femtosecond laser systems but, as described in this book, advances in semiconductor superlattice technology are leading to compact “electronic” sources such as the quantum cascade laser, two-terminal “Gunn” type oscillators and even a THz frequency amplifier. These advances towards electronic (as opposed to optical) THz systems mean that the technology will become portable and much less costly.

Terahertz remote sensing is also discussed with the possibility of detection over distances of up to 30m using existing technology or even through the use THz waves generated locally in the vicinity of a target using only air as the transducer.