An extended cavity diode-pumped femtosecond Yb:KGW laser for applications in optical DNA sensor technology based on fluorescence lifetime measurements.

A reliable and power-scalable extended cavity diode-pumped passively mode-locked Yb:KGW laser generating ~200 fs long pulses at a repetition rate of 15 MHz was developed and characterized. The laser delivered up to 150 mW of average power at fundamental wavelength of 1040 nm, corresponding to a pulse energy of 10 nJ. The laser radiation was frequency-doubled in a single pass configuration within a nonlinear BIBO crystal to produce femtosecond green radiation at 520 nm with peak power of ~200 W.

Synthesis and optical properties of thiol-stabilized PbS nanocrystals.

Thiol-capped water-soluble PbS nanocrystals (NCs) stabilized with 1-thioglycerol, dithioglycerol, or a mixture of 1-thioglycerol/dithioglycerol (TGL/DTG) were prepared via one-stage synthesis at room temperature. We found that NCs stabilized with a TGL/DTG mixture show efficient and stable infrared photoluminescence centered in the second "biological window" (1050-1200 nm). Under optimized conditions, full width at half-maximum of the PL emission peak was from 70 to 100 nm.