We assess the relative merits and prospects of integrated-optics in comparison with microoptic and fiber-based techniques, Firstly, the market for fiber-optic components for telecommunications is analyzed, Secondly, t...
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We assess the relative merits and prospects of integrated-optics in comparison with microoptic and fiber-based techniques, Firstly, the market for fiber-optic components for telecommunications is analyzed, Secondly, the technological issues which make integrated optics quite different from integrated electronics will be discussed, Thirdly, a specific comparison between the potential of the competing optical technologies will be made for the polarization-diversity hybrid and the optical wavelength (de)multiplexer, two optical devices used in networks that are based on optical frequency division multiplexing (OFDM).
The Vanderbilt free-electron laser (FEL) is a continuously tunable source of pulsed, mid-infrared radiation. FEL applications research has been underway for a decade. Recent experimental advances in FEL ablation of so...
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The Vanderbilt free-electron laser (FEL) is a continuously tunable source of pulsed, mid-infrared radiation. FEL applications research has been underway for a decade. Recent experimental advances in FEL ablation of soft tissue indicate the potential for FEL-based protocols in surgery and medicine, In anticipation of these medical applications, the Vanderbilt FEL is being upgraded to meet the reliability and performance standards for a medical laser. Facilities for laser surgery have been constructed and equipped and medical delivery systems are being developed for pre-clinical and clinical research.
Laser-induced fluorescence detection has become the detection strategy of choice in many large-scale DNA sequencing applications due to its ease of implementation, sensitivity and the ability to identify the constitue...
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Laser-induced fluorescence detection has become the detection strategy of choice in many large-scale DNA sequencing applications due to its ease of implementation, sensitivity and the ability to identify the constituent bases of DNA in a single separation lane when the probes used have a distinct spectral characteristic, While the common strategy is to use fluorescent dyes which show absorption and emission properties in the visible region (400-600 mm) of the electromagnetic spectrum, our efforts have been directed toward developing near-IR (700-1000 nm) fluorescence as a viable detection strategy for DNA sequencing, The principle advantages of near-IR fluorescence include, the lower background levels observed in this spectral region, improving the signal-to-noise ratio (SNR) and the ability to use simple diode lasers and avalanche photodiodes to construct an all-solid-state laser fluorescence detector, In this paper, we will discuss our results concerning the use of near-IR fluorescence detection for DNA sequencing carried out in a capillary gel column, where the capillary column has an internal diameter of 75 mu m, and the loading level of DNA onto this column is in the nL regime, requiring ultra-sensitive detection, In addition, we will discuss our efforts toward the development of a highly efficient, single lane, single fluor, base-calling strategy using lifetime discrimination of heavy-atom modified near-IR dyes, The dyes developed for this application contain an intramolecular heavy atom (halogen) on a remote section of the chromophore, resulting in a perturbation in the fluorescence lifetime without altering the absorption or emission maximum of the base chromophore. This will allow the dye series to be excited with a single laser with the fluorescence processed on a single detector and the identity of the terminal base accomplished via lifetime discrimination, In order to effectively carry out lifetime measurements during capillary electrophoretic separation
Near-field optical microscopy and spectroscopy is emerging as a powerful tool for the investigation of semiconductor structures, Tunable excitation combined with sub-wavelength resolution is providing an unprecedented...
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Near-field optical microscopy and spectroscopy is emerging as a powerful tool for the investigation of semiconductor structures, Tunable excitation combined with sub-wavelength resolution is providing an unprecedented level of detail on the local optical properties of semiconductor structures, Recent near-field optical studies have addressed issues of laser diode mode profiling, minority carrier transport, near-field photocurrent response of quantum-well structures and laser diodes, imaging of local waveguide properties, and location and studies of dislocations in semiconductor thin films, We present results on the intrinsic resolution limitations of near-field photoconductivity in quantum-well heterostructures and demonstrate that the resolution depends strongly on the amount of evanescent and propagating field components in the semiconductor, Spectroscopic mode-profiling of high-power laser diode emission details the spatial dependence of multiple spectral modes, This paper presents an overview of NSOM techniques for semiconductor systems, its limitations, and present status.
In this paper, we review recent advances in optical parametric oscillators, with particular emphasis on high repetition rate, femtosecond optical parametric oscillators, We present results for several of these systems...
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In this paper, we review recent advances in optical parametric oscillators, with particular emphasis on high repetition rate, femtosecond optical parametric oscillators, We present results for several of these systems, and show that they offer a unique combination of short pulse durations, high average powers, high repetition rates, and broad tunability which have not been previously available from a single source, We conclude by looking at some applications in the field of ultrafast semiconductor spectroscopy, some of which are only now possible because of the femtosecond optical parametric oscillator, It is, therefore, apparent that this unique device offers greater flexibility than previously available sources, and will enable many new and novel experiments in many areas of science and technology.
An efficient nitrogen laser has been developed. The exciter of the nitrogen laser employs a magnetic pulse compression circuit. A laser pulsed energy of 20 mJ is achieved under a single-pulsed mode, with an efficiency...
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An efficient nitrogen laser has been developed. The exciter of the nitrogen laser employs a magnetic pulse compression circuit. A laser pulsed energy of 20 mJ is achieved under a single-pulsed mode, with an efficiency of 1.3% to the output energy of the exiter, and 0.43% to the charging energy. Several types of electrodes were tested. A maximum efficiency and laser light pulse energy are obtained with triangular-rectangular electrodes and at a laser gas pressure of about 100 Torr.
The AT&T subrate data cross-connect system (SRDC) brings the capabilities of the digital access and cross-connect system (DACS) used primarily for analog circuits to the digital data world, including the capabilit...
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The AT&T subrate data cross-connect system (SRDC) brings the capabilities of the digital access and cross-connect system (DACS) used primarily for analog circuits to the digital data world, including the capability of mechanized remote provisioning and maintenance. The SRDC performs DACS-equivalent functions on 64 kbit/s channels of the Digital Data System (DDS) and other similar emerging data networks at the 2.4, 4.8, 9.6, and 56 kbit/s rates. An SRDC-equipped DACS frame can process both voice and digital data in a shared arrangement. It can also provide all the functions necessary for a DDS hub office environment, including subrate multiplexing, multipoint functions, dataport error correction and secondary channel processing. The operational functions supported by SRDC include circuit testing, facility performance monitoring, circuit and equipment provisioning, memory administration, and equipment maintenance.
Recent advances in optical transmission technologies hold forth the promise of abundant and low-cost bandwidth. Parallel advances in the fundamental technologies required for the construction of switching equipment re...
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Recent advances in optical transmission technologies hold forth the promise of abundant and low-cost bandwidth. Parallel advances in the fundamental technologies required for the construction of switching equipment result in a plethora of emerging technologies available for use by the systems designers seeking to define a wide-band ( > 100 Mbits/s per channel) communications system. This paper presents a concept for such a system intended for use in the local access segment of a communications network. Both the proposed underlying technologies and the systems concepts used in applying those technologies will be presented.
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