Diode lasers spectral properties

Oswald B, Patsenker L, Duschl J, Szmacinski H, Wolfbeis OS, Terpetschnig E (1999) Synthesis, spectral properties, and detection limits of reactive squaraine dyes, a new class of diode laser compatible fluorescent protein labels. Bioconjugate Chem 10 925-931... 

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. 

As expected, solutions containing mixtures of nanocrystal sizes exhibited spectral profiles corresponding to the sum of the spectra of the individual sizes (Fig. 5.3). The initial PL peak positions of 2.8 and 5.6-nm CdSe nanocrystals in toluene solution were at 541 and 636 nm, respectively. We incorporated the CdSe nanocrystal mixtures into polymer matrices rationally selected based on polymer-sensing properties (Table 5.1). CdSe nanocrystals exhibited spectral shifts upon their immobilization in polymer films and photoactivation with the 407-nm diode laser. Photoactivation is an important aspect of the performance of the CdSe and other semiconductor crystals as chemical sensor materials.16 Different spectral shifts of steady-state PL emission and different emission intensity were observed upon incorporation of the 2.8 and 5.6-nm CdSe nanocrystals in polymer films as illustrated in Fig. 5.4. Polymer 2 (PMMA) was selected for the detailed evaluation because it has been used previously as a matrix for incorporation of CdSe nanocrystals.1636... 

The results of a comparison of spectral and luminescence properties of YGOB and certain other yttrium-containing crystals indicate that these crystals are very good elements for the construction of diode-pumping tunable lasers with super-... 

Squaraines with ring substituents which absorb and emit in the red and near-infrared regions have also been developed [72]. When compared to conventional Cy5—NHS systems (open chain), these derivatives have several advantages. For example, these compounds can be excited not only with red lasers but also with blue lasers or with luminescent diodes being useful compounds, they can be excited all over the visible range of the electromagnetic spectrum. These compounds are particularly useful in biomedical applications due to their favorable spectral and photophysical properties, such as fluorescence [72]. 

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