Highspeed wavelengthswept semiconductor laser with a. High power, long wavelength semiconductor disk lasers for continuous and modelocked operation. Advances in material purity and epitaxial growth techniques have led to a variety of semiconductor lasers covering a wide wavelength range of 0. The development during the 1970s of gaas semiconductor lasers. Stanford libraries official online search tool for books, media, journals, databases, government documents and more. The longwavelength side approaching the band edge is quite abrupt. Nowadays, semiconductor lasers have been extensively used in many practical applications such as fibreoptic communications, optical storage and laser spectroscopy. Short wavelength radiation emitted from the top surface of the underlying vcsel is transmitted through the lower mirror of the long wavelength vcsel. Organic semiconductor lasers that can deliver intense coherent light across the full visible spectrum have been intensively pursued during the past decade 16 for their practical applications that range from multiband communication to fullcolor laser displays 711. A vcsel for emitting long wavelength light including a gaas 111 substrate element, a first mirror stack with mirror pairs in a gaasalgaas material system lattice matched to a gainasn active region with an active structure sandwiched between a first cladding region adjacent the first mirror stack and a second cladding region, the active structure including a nitride based. Such a design enables considerably thinner mirror structures than the conventional design, where the semiconductor dbr is finished with mere metal layers. Longwavelength semiconductor lasers in searchworks catalog. Covering a wide range of key topics, such as operating principles, thermal management, nonlinear frequency conversion, semiconductor materials, short pulse generation, electrical pumping, and laser applications, the book provides readers with a.
The research of long wavelength semiconductor lasers is important with respect to the practical applications in a wide spectral range. 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. There is an active field of the competitive developments of laser versions based on quite different operation mechanisms. Pdf on jun 17, 2015, prasanta kumar basu and others published semiconductor laser theory find. Introduction semiconductor diodes and lasers are nowadays widely used in communication, electronic equipment, e. The longestwavelength laser6 demonstrated to date, however, emits at 5. Recent progress of high power semiconductor lasers for. Semiconductor lasers or laser diodes play an important part in our everyday lives by providing cheap and compactsize lasers. Since its invention in 1962, the semiconductor laser has come a long way. The development during the 1970s of gaas semiconductor lasers, emitting in the nearinfrared region of 0. The reflectivity of the semiconductor dbr section is enhanced by finishing the dbr with a thin low refractive index layer and a highly reflecting metal layer.
However, the tuning speed demonstrated so far has been. In the first approach we showed the use of vshaped weaker waveguide in the ncladding layer dramatically reduces vertical beam diver. It is commonly believed that, at room temperature and above, nonradiative auger re combination is the dominant physical mechanism respon sible for such sensitivity. Only the photons that leave the cavity from the mirrors constitute useful output. We report in this paper the realization of distributed feedback dfb qcls, made of inas and alsb, that demonstrated a continuous wave cw and. The guided modes are transverse magnetic polarized surface waves that propagate at the metal pd or tiausemiconductor interface between the laser top contact. Long wavelength gasbbased quantum well lasers have been optimized for high coupling efficiency into an optical system. Two approaches were used to reduce the vertical farfield. Ingaasp lasers operating at longer wavelengths were. In spite of the fact that semiconductor lasers do not produce a beam with characteristics as desired in other types of lasers, their small size, low power consumption and relatively high. Light is emitted at a junction between two regions of opposite doping as shown in gure 4.
Long wavelength radiation is preferably emitted from the top surface of the. The beam divergence of semiconductor lasers is much greater than most of the lasers, depending on temperature, therefore ranging from 125 to 400 milli radians. Modehopping free singlefrequency operation has been demonstrated in extendedcavity semiconductor lasers with sophisticated grating fiber designs. Optical pumping of semiconductor lasers has a long history, where optical. We also need expressions for the light coming out of the laser. Use features like bookmarks, note taking and highlighting while reading longwavelength infrared semiconductor lasers wiley series in lasers and applications book 8. Of the material systems these lasers are based on, only the inasgainsb material system4,5 can in principle produce an 812mm laser. Here, we report extremely high temperature continuouswave cw operation of qd lasers on gaas substrate emitted at 0nmrange by enhancing gain and increasing the quantizedenergy separation of the qd. Semiconductor lasers utilize a semiconductor as the gain medium. A long wavelength vcsel according to the present invention is optically coupled to and optically pumped by a shorter wavelength, electrically pumped vcsel. Semiconductor lasers types, applications, construction. Towards high power flipchip longwavelength semiconductor. Pdf although diode lasers are almost ideal sources for ultrahighspeed data. Semiconductor lasers in this laboration you will become familiar with the properties of semiconductor lasers and their use in absorption spectroscopy.
Longwavelength semiconductor lasers govind agrawal. Ideal performance of cascade and noncascade intersubband. Longwavelength infrared semiconductor lasers wiley. Longwavelength semiconductor lasers for spectroscopic gas. With the progress of optical transmission technology, various kinds of semiconductor lasers have been developed for the application to wavelength division multiplexing, high speed, low power consumption, and photonic integration. The mode of operation is somewhat di erent than that of the laser described in the previous chapter. Generation of optical pulses from long wavelength semiconductor lasers using qswitching technique article pdf available january 2011 with 52 reads how we measure reads. Pdf strained layer quantum well semiconductor lasers. Semiconductor lasers and light emitting diodes 1222 for a 250 m long semiconductor laser and an effective index of 3. Longwavelength quantum dot fp and dfb lasers for high.
Semiconductor lasers are attractive for many reasons including their lowcost, compact nature, potential for mass production, and the capacity to easily integrate them with other systems. Van dongen, progress in longwavelength strainedlayer. Roomtemperature 2d semiconductor activated vertical. The roughly constant energy limit of band filling just mentioned implies a wavelength tuning range that increases roughly as the square of the center wavelength.
Temperature dependence of long wavelength semiconductor. Each semiconductor laser has got competitive advantage with respect to different parameter. Long wavelength side an overview sciencedirect topics. Longwavelength semiconductor lasers for spectroscopic gas sensing longwavelength semiconductor lasers for spectroscopic gas sensing prairie, michael w. Their theoretical description is important not only from a fundamental point of view, but also in order to generate new and improved designs. Benefitting from advanced research over the years, the properties of such lasers have substantially improved, in particular, becoming more powerful, efficient.
Pdf fast phenomena in semiconductor lasers researchgate. High power, long wavelength semiconductor disk lasers for. King abdulaziz city for science and technology, kacst, national nanotechnology research center, riyadh, saudi arabia. Pdf generation of optical pulses from long wavelength. Progress in longwavelength strained compressive and tensile ingaasp quantum well semiconductor lasers and amplifiers for applications in optical fibre communication systems is. The practical use of long wavelength semiconductor laser diodes is impaired by an extreme sensitivity of thresh old current to temperature. 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. Most of them are electrically pumped laser diodes, where electronhole pairs are generated by an electrical current in a region where ndoped and pdoped semiconductor materials meet. Otsubo et al longwavelength semiconductor lasers on ingaas ternary substrates with excellent temperature characteristics grown by the bridgman method and the gaas source crystals are set as shown in figure 7. Nevertheless, electrically pumped organic lasers remain a grand challenge and. However, there are also optically pumped semiconductor lasers, where carriers are generated by absorbed pump light. Waveguide design optimization for long wavelength semiconductor lasers with low threshold current and small beam divergence abdulrahman almuhanna, abdullah alharbi, abdelmajid salhi. The wavelength spacing of the longitudinal modes varies slowly, and if the laser operates at approximately 1550 nm, the longitudinal modes are separated by about 1.
618 477 53 596 904 1383 957 1645 1035 879 539 782 1669 1072 1120 1223 1456 641 484 887 1 1225 29 872 1273 1122 634 1055 542 99 1513 1507 1254 1160 1362 905 115 1025 27 1009 951 1126 1014