A CW green laser emission by self-sum-frequency-mixing in Nd:GdCOB crystal

Abstract

Phenyl acetic acid, a metabolite of 2—phenyl ethylamine, acts as a neuromodulator in the nigrostriatal dopaminergic pathway neuromodulator stimulating the release of dopamine. The evaluation of phenyl acetic acid concentration in the biological fluid reflects phenyl ethylamine levels thus allowing the assessment of the modulatory role of this endogenous substance. Changes in biological fluids levels of 2—phenylethylamine and/or in its metabolite have been reported in affective disorders, such as depression and schizophrenia. Recently, the occurrence of the “attention deficit hyperactivity syndrome” has been frequently reported in childhood population and involvement of dopaminergic dysfunction in this disease has been suspected. A fast, reliable and reproducible method for the determination of phenyl acetic acid in human blood, is therefore needed in order to have a screening tool for monitoring both healthy childhood population and suspected “attention deficit hyperactivity syndrome” patients. The gas chromatographicmass spectrometric method here described makes use of a deuterated internal standard in order to overcome problems related to the lack of reproducibility often encountered when a derivatization step is performed.

Three-wavelength green generation in Nd:GdCOB slab crystal based on self-frequency conversion

“…At 530 nm, the highest output power was obtained to be 1.32 W under a pump power of 20.1 W [10]. Besides, a 1.73 W output power self-sum-frequency (SSF) green laser at 538 nm has been presented [11]. So far, multi-wavelength lasers were seldom reported in Nd:GdCOB crystal.…”

High power single-longitudinal-mode cyan laser at 500.8 nm

“…Since 1990s, many studies of sum frequency tech nology have been carried out, and then obtained many new wavelengths, such as green laser at 538 nm, by self sum frequency mixing of both fundamental infrared laser waves (1061 and 1091 nm), with 18.2 W of diode pump power, a maximum output power of 1.73 W has been achieved [8], 531 nm, with a diode pump power of 8.3 W, laser at 531 nm of 148 mW is obtained [9], blue green laser at 497 nm, by self sum frequency generation of the 936 and 1060 nm, with a diode pump power of 14.3 W, the maximum output power was 75 mW [10], yellow laser at 592 nm, with a diode pump power of 9.8 W, laser at 592 nm of 37 mW is obtained [11], orange laser at 600 nm, by intracavity sum frequency generation of the 1085 and 1342 nm laser lines of two Nd:YVO 4 lasers, laser at 600 nm of 1.06 W is obtained. The power stability in 30 min is better than 2.8% [12], and so on.…”