Diode infrared

The main use of elemental As is in alloys with Pb and to a lesser extent Cu. Addition of small concentrations of As improves die properties of Pb/Sb for storage batteries (see below ), up to 0.75% improves the hardness and castabilily of type metal, and 0 5-2.0% improves the sphericity of Pb ammunition. Automotive body solder is Pb (92%),, Sb (5 0%), Sn (2.5%) and As (0.5%). Intcrnxitallic compounds with Al, Ga and In give the 111-V semiconductors (p 255) of which GaAs and InAs are of particular value for light-emitting diodes (LEDs), tunnel diodes, infrared emitters, laser windows and Hall-effect devices (p. 258). 

Use Phosphors, transistors and diodes, infrared-transmitting glass. 

Sulphur hexafluoride still commands considerable attention. Single-photon excitation of V3 = 1 has been studied in high-resolution diode-infrared laser... 

The infrared photochemistry of SF continues to attract considerable interest. One important study involves excitation of SFg in high-resolution diode-infrared laser double resonance experiments. At high intensities, and 30 ps infrared pulses, spectral hole burning is observed at energies corresponding to the absorption of between 4 and 5 photons per molecule (Reiser et al. cf. Sharp et al.). 

Figure 9 (A) Spectral stripping of components from the tunable diode laser infrared spectrum of cigarette smoke. From bottom to top ethylene, acrolein, methanol, and comparison with hydrazine. The reference spectrum is the lower of the two traces in each case. (B) Expanded view of the residual spectrum compared to that of hydrazine. (Reprinted with permission from Plunkett S, Parrish ME, Shafer KH, Nelson D, Shorter J, and Zahniser M (2001) Time-resolved analysis of cigarette combustion gases using a dual infrared tunable diode infrared laser system. Vibrational Spectroscopy 27 53-63 Elsevier.)...

A very widely employed method for the measurement of spin-orbit state-specific rate constants is the time-resolved measurement of the concentrations of individual atomic levels after formation of these species from a suitable precursor, either by flash photolysis [13], or, more recently, by laser photodissociation. The concentrations of the various atomic reactant states are monitored by atomic absorption or fluorescence spectroscopy using atomic emission sources [14], or, for spin-orbit-excited states, by observation of the spontaneous infrared emission [15-18]. Recently, Leone and co-workers have utilized gain/absoiption of a colour centre and diode infrared laser to probe the relative populations of ground and spin-orbit excited halogen atoms produced in a chemical reaction [19] and also by photodissociation [20],... 

Even more remarkable is tlie fact tliat tliese infrared diode lasers have sufficient resolution to measure tlie Doppler... 

Figure C3.3.4 shows a schematic diagram of an apparatus tliat can be used to study collisions of tlie type described above [5, 9,12,16]. Donor molecules in a 3 m long collision cell (a cylindrical tube) are excited along tlie axis of tlie cell by a short-pulse excimer laser (typically 25 ns pulse widtli operating at 248 mil), and batli molecules are probed along tliis same axis by an infrared diode laser (wavelengtli in tlie mid-infrared witli continuous light-output...

The data obtained in tlie infrared-diode-laser-probe studies described above provides quenching infonnation at a given substrate donor energy E. By varying tlie laser excitation wavelengtli for production of vibrationally hot... 

A diode, or semiconductor, laser operates in the near-infrared and into the visible region of the spectmm. Like the mby and Nd YAG lasers it is a solid state laser but the mechanism involved is quite different. 

Raman measurements [INFRARED TECHNOLOGY AND RAMAN SPECTROSCOPY - RAMAN SPECTROSCOPY] (Voll4) -role in LEDs piGHT GENERATION - LIGHT-EMITTING DIODES] (Vol 15)... 

Lasers having wavelengths ranging from the deep uv to the near infrared have been used in Raman spectroscopy. In industrial laboratories, the most common laser is the Nd YAG operating at 1.06 pm. Increasingly, diode lasers or other lasers operating in the 750—785-nm region are encountered. These... 

For the visible and near-ultraviolet portions of the spectmm, tunable dye lasers have commonly been used as the light source, although they are being replaced in many appHcation by tunable soHd-state lasers, eg, titanium-doped sapphire. Optical parametric oscillators are also developing as useful spectroscopic sources. In the infrared, tunable laser semiconductor diodes have been employed. The tunable diode lasers which contain lead salts have been employed for remote monitoring of poUutant species. Needs for infrared spectroscopy provide an impetus for continued development of tunable infrared lasers (see Infrared technology and RAMAN spectroscopy). 

At low background flux this gives the temperature dependence of the Z9 shown in Eigure 4. At high flux, the Z9 equation (eq. 37) reduces to equation 12 except for a factor of (2) which is a result of the random recombination process not present in diodes. The scene sensitivity of a scanning photoconductor array infrared camera is ca 0.15°C. 

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