Wavelength laser diode

Chu S N G 1993 Long wavelength laser diode reliability and lattice imperfections MRS Bull. 17 43... 

Figure 4.1.5. Schematic of a three-wavelength laser-diode array spectrometer for making reflection measurements.

Dual wavelength laser diode excitation source for 2D photoacoustic imaging, T. J. Allen and P. C. Beard, Proc. SPIE, 2007, 6437, 64371U/1. 

GaAs, GaAlAs, and GaP based laser diodes are manufactured using the LPE, MOCVD, and molecular beam epitaxy (MBE) technologies (51). The short wavelength devices are used for compact disc (CD) players, whereas the long wavelength devices, mostly processed by MBE, are used in the communication field and in quantum well stmctures. 

GaUium-based laser diodes have also lost some of the market in telecommunications to indium-based devices. Optical fiber systems moved to the use of longer wavelengths for long distance networks. 

In practical application, Raman sensors exclusively use frequency-stabilised laser sources to compensate for the low intensity of the Raman radiation. For Raman sensors, prevalently compact high-intensity external cavity laser diodes are used, operated in CW (continuous wave) mode. These diode lasers combine high intensity with the spectral stability required for Raman applications and are commercially available at various wavelengths. 

How can phase-modulation fluorometry contribute to this health-care need It now seems possible to construct a lifetime-based blood gas catheter (Figure 1.3), or alternatively, an apparatus to read the blood gas in the freshly drawn blood at the patient s bedside. To be specific, fluorophores are presently known to accomplish the task using a 543-nm Green Helium-Neon laser,(18 19) and it seems likely that the chemistries will be identified for a laser diode source. The use of longer wavelengths should minimize the problems of light absorption and autofluorescence of the samples, and the use of phase or modulation sensing should provide the robustness needed in a clinical environment. For the more technically oriented researcher, we note that the... 

The characteristic distances for FRET can be reliably calculated from the spectral properties of the donor (D) and acceptor (A). Importantly, FRET can be reliably predicted to occur for any D-Apair, so that the system can be wavelength-adjusted to match the wavelengths of laser diode sources. The extent of FRET depends on the proximity of the donor and acceptor. 

Additional laser diode technologies recently reported include a continuous-wave rhodamine 700 dye laser with a maximum wavelength output at 758 nm, powered by two laser diodes each operated with two standard AA batteries (RDT E division of the US Naval Command, Control, and Ocean Surveillance Center, San Diego, California), and a tunable laser diode with output laser wavelengths of 650, 780, 850, and 1320 nm (New Focus, Mountain View, California). 

The availability of low-cost laser diodes has expanded the applications of NIR dyes.(34) NIR dyes have been used in analytical applications such as fiber probes(39,79) and the detection of caustic brine.(89) However, most of the NIR dye applications have been in electrophotography for the manufacturing of office products such as laser printers and facsimiles. The wavelength of the lasers is not necessarily matched to the absorbance maxima of the dyes. Therefore, an understanding of the spectroscopic properties of NIR dyes and their ability to be chemically tuned is necessary to further expand the use of these dyes. 

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