Because of very strong molecular absorption between 2 mm to mm, compact semiconductor lasers in this spectral range are ideal components for a wide variety of applications ranging from ultrasensitive detection of molecules, to the study of fine structures of molecules, to studies of the origin of the universe. The longwavelength infrared spectrum spanning from 2 m m to m m is technologically signi. Ideal performance of cascade and noncascade intersubband. Midinfrared spectroscopy using qcls is particularly interesting since most. Under cw operation many leadsalt lasers with cleaved facets operate in a single frequency. An immense slab of continuous melt processed neodymium doped laser glass for use on the national ignition facility. Longwavelength infrared semiconductor lasers wiley series in.
We experimentally demonstrate a sixfold enhancement in photoluminescence from ultrathin total thickness. Semiconductor devices have become indispensable for generating electromagnetic radiation in everyday applications. The practical use of long wavelength semiconductor laser diodes is impaired by an extreme sensitivity of thresh old current to temperature. Terahertz semiconductorheterostructure laser nature. We report in this paper the realization of distributed feedback dfb qcls, made of inas and alsb, that demonstrated a continuous wave cw and a single mode emission at a. Longwavelength semiconductor lasers govind agrawal. Fabrication of defect free iiinitride materials, us patent number 6271104, granted august 7, 2001 18.
High tuning stability of sampled grating quantum cascade. Quantum cascade qc lasers working in the midinfrared range of the electromagnetic spectrum have shown high performances now, and the extension to the farinfrared i. Temperature dependence of long wavelength semiconductor. It is commonly believed that, at room temperature and above, nonradiative auger re combination is the dominant physical mechanism respon. Semiconductor lasers emitting at more than two micrometers have many applications such as in trace gas analysis, environmental monitoring, and industrial. Quantum cascade laser basics wavelength electronics.
Analytical and numerical models of the emission process via a. Long wavelength infrared photodetectors growth, characterization and fabrication. Exploration of bi and tl containing iiiv materials for uncooled longwavelength infrared photodetector applications. The first comprehensive treatment of longwavelength laser technology. Infrared emission from the substrate of gaasbased semiconductor lasers. For these reasons, we believe that the aq6375 can contribute to the improvement and wider use of semiconductor lasers. Infrared and visible semiconductor lasers springerlink. The technical problems that must be solved to achieve efficient operation of longwavelength semiconductor lasers will then be outlined. Longwavelength semiconductor lasers on ingaas ternary. Wasserman1 1department of electrical and computer engineering, the university of texas at austin, austin, tx 78712, usa 2department of physics and applied physics, umass lowell, one university ave, lowell.
Longwavelength semiconductor lasers for spectroscopic gas sensing longwavelength semiconductor lasers for spectroscopic gas sensing prairie, michael w. Wavelength infrared semiconductor lasers wiley online. Today, qcls provide high optical output power and excellent beam quality 2. The development during the 1970s of gaas semiconductor lasers. Longwavelength semiconductor lasers for spectroscopic gas. Subterahertz and terahertz generation in longwavelength. She is a pioneer in modern epitaxial techniques for semiconductors such as low pressure metalorganic chemical vapor deposition mocvd, vapor phase epitaxy vpe, molecular beam epitaxy mbe, gasmbe, and mombe. For example, in the late 1990s, the intersubband absorption in the qds led to the development of midwavelength and longwavelength infrared photodetectors 30, 31. Waveguide design of long wavelength semiconductor laser.
Longwavelength infrared semiconductor lasers wiley series in lasers and applications book 8 kindle edition by choi, hong k download it once and read it on your kindle device, pc, phones or tablets. This paper will summarize our research in midinfrared semiconductor lasers, focusing mainly on the gainassbalgaassb material system. Visible and infrared diode lasers are at the core of information technology, and. Moreover, because doped layers and metallic contacts are not necessary for the operation of the quantum fountain laser, free carrier and plasmon absorptions can be minimised, thus allowing long wavelength operation. Of particular interest are the leadsalt semiconductor lasers covering a large spectral range 2. Modeling and analysis of al free near and midinfrared semiconductor lasers. Laser waveguides based on surface plasmons at a metalsemiconductor interface have been demonstrated by use of quantum cascade qc lasers emitting in the 8 11. Their wide tuning range and fast response time allow for faster and more precise compact trace element detectors and gas analyzers that. Hightemperature longwavelength verticalcavity lasers a dissertation submitted in partial satisfaction of the requiremments for the degree of doctor of philosophy in electrical and computer engineering by near m. The regular arrangement of the rods provides the unique properties.
Longwavelength laser will be able to take medicine. Enhanced emission from ultrathin long wavelength infrared. Bowers, long wavelength high speed semiconductor lasers with carrier. Advances in material purity and epitaxial growth techniques have led to a variety of semiconductor lasers covering a wide wavelength range of 0. Typical problems with laser crystals for solidstate midir lasers are the limited transparency range of the. In addition, this geometry offers the possibility to add technological elements such as, intracavity heat spreaders for thermal management kemp et al. Aq6375 optical spectrum analyzer for long wavelength band. There is an active field of the competitive developments of laser versions based on quite different operation mechanisms. Longwavelength infrared semiconductor lasers wiley. Please help improve this article by adding citations to reliable sources.
In general, the maximum operating temperature of leadsalt lasers 8 coherent semiconductor sources in the longwavelength ir spectrum peaks at between 4 and 5 mm, and decreases at either shorter or longer wavelengths. After an introduction on potential applications, we discuss how the combination of vertical. The threshold and temperature characteristics of such lasers are considered. Longwavelength semiconductor lasers govind agrawal springer. Pdf infrared emission from the substrate of gaasbased. Long wavelength dh, sch, and mqw lasers based on sb, us patent number 6108360, granted august 22, 2000 19. The main challenges for the long wavelength semiconductor lasers. The extension of the available spectral range covered by quantum cascade lasers qcl would allow one to address new molecular spectroscopy applications, in particular in the long wavelength domain of the midinfrared. The research of long wavelength semiconductor lasers is important with respect to the practical applications in a wide spectral range.
Use features like bookmarks, note taking and highlighting while reading longwavelength infrared semiconductor lasers wiley series in lasers and applications book 8. Quantum cascade laser technology quantum cascade lasers qcls are a type of semiconductor laser which utilizes epitaxially grown quantum wells that contain electrons in lasing states. Manijeh razeghi is an iranianamerican scientist in the fields of semiconductors and optoelectronic devices. Hightemperature longwavelength verticalcavity lasers. This article needs additional citations for verification. Device characteristics of longwavelength lasers based on. Abstractterahertz quantum cascade laser sources with intracavity nonlinear frequency mixing are the first roomtemperature electrically pumped monolithic semiconductor sources that operate in the 1. Lattice parameter engineering for iiiv long wave infrared photonics pdf gasbbased typei qw diode lasers pdf gasbbased typei qw leds and addressable arrays operated at wavelengths up to 3. Since its invention in 1962, the semiconductor laser has come a long way. Silicon waveguided components for the longwave infrared.
The current state of the field of semiconductor lasers operating in the spectral range near 1. The development during the 1970s of gaas semiconductor lasers, emitting in the nearinfrared region of 0. The optical pumping scheme enables a simpler design of the active region than electrically pumped intersubband lasers. Longwavelength infrared semiconductor lasers wiley series in lasers and applications choi, hong k.
In the first approach we showed the use of vshaped weaker waveguide in the ncladding layer dramatically reduces vertical beam diver. Yag lasers, many fiber lasers and the most powerful laser diodes, emit nearinfrared light. Broadband tuning of continuous wave quantum cascade lasers. The guided modes are transverse magnetic polarized surface waves that propagate at the metal pd or tiau semiconductor interface between the laser top contact and the active region. Unfortunately, for emission wavelengths longer qw emission to longer. Longwavelength laser will be able to take medicine fingerprints 19 december 2012 photonic crystal for a 6 gigahertz laser. Over the past few years, quantum cascade lasers qcls have found a tremendous number of applications, from spectroscopy to infrared countermeasures and free space optical communications 1. There are comparatively few laser sources for the mid and farinfrared spectral regions. Semiconductor disk lasers for the generation of visible. Broadband spectral tuning in the long wavelength range greater than 10. Since they are relatively well developed, the bulk of this chapter is devoted to their study.
Quantum cascade lasers qcl are semiconductor lasers that emit in the mid and longwave ir bands, and are finding new applications in precision sensing, spectroscopy, medical, and military applications 1. Optical pumping of semiconductor lasers has a long history, where optical pumping had been. Compact semiconductor lasers emitting near room temperature are very much needed for many applications ranging from ultra sensitive detection of molecules, to the study of. Laser waveguides based on surface plasmons at a metal semiconductor interface have been demonstrated by use of quantum cascade qc lasers emitting in the 8 11. However, high performance in lowfrequency range is difficult because converted terahertz waves suffer from significantly high absorption in waveguides. Long wavelength gasbbased quantum well lasers have been optimized for high coupling efficiency into an optical system.