Solid-state Yellow Laser Research Articles

Optical properties of Dy3+ ion in GGG laser crystal

High optical quality Dy3+-doped Gd3Ga5O12 (abbreviated as Dy : GGG below) crystal was grown by the Czochralski technique along the (1 1 1) orientation. The absorption spectrum, fluorescence spectrum and fluorescence decay curve of Dy : GGG have been recorded at room temperature. Based on the Judd–Ofelt (J–O) theory, the intensity parameters from the measured line strengths were determined. The J–O parameters were used to predict radiative transition probabilities, radiative lifetime and branching ratios for various excited levels of the Dy : GGG crystal. In the visible region, one intense fluorescence band was observed at 581 nm, corresponding to the 4F9/2 → 6H13/2 transition. The room-temperature fluorescence lifetime of this transition of Dy3+ ion in the GGG crystal was measured to be 0.79 ms, and the luminescent quantum efficiency of the 4F9/2 level was evaluated to be 71.4 %. The emission cross-sections of the 4F9/2 → 6H13/2 transition were estimated by the use of the Füchtbauer–Ladengurg method. The research on the emission at 581 nm indicates the possibility of using a commercially available laser diode of 353 nm as a pumping source for a solid-state yellow laser.

Float zone growth of Dy:GdVO 4 single crystals for potential use in solid-state yellow lasers

Single crystals of dysprosium-doped gadolinium orthovanadate (Dy:GdVO 4) were successfully grown by the floating zone method and their fluorescence properties were investigated. The as-grown crystals did not contain any macroscopic defects such as cracks and inclusions for any Dy-concentration of up to 4 at%. Every crystal showed optical homogeneity under observation with a polarizing microscope; that is, no low-angle grain boundaries and growth striations were detected. In the visible region, two distinct fluorescence bands were observed around 480 and 575 nm, corresponding to 4F 9/2→ 6H 15/2 and 4F 9/2→ 6H 13/2 transitions, respectively. The excitation spectrum for the emission of 573 nm indicates the possibility to use a commercially available laser diode of 450 nm as a pumping source for solid-state yellow laser.

An 8.1 W diode pumped solid-state quasi-continuous-wave yellow laser at 589 nm by intracavity sum-frequency mixing generation

We report an L-shaped symmetrical co-folding-arm plane–plane diode pumped solid-state yellow laser at 589 nm by using intracavity sum-frequency mixing. By carefully designing the cavity and employing various techniques to optimize the laser’s specifications, a quasi-continuous-wave (QCW) free-oscillation yellow laser source, which has an average output power of 8.1 W, a beam quality factor of M 2 = 2.3, and a repetition rate of 1.1 kHz, is developed. The generation of yellow laser at 589 nm is achieved by intracavity sum-frequency mixing between the laser lines at 1319 nm and 1064 nm of an Nd:YAG laser in a KTP crystal. To the best of our knowledge, the 8.1 W output at 589 nm is higher than any other diode pumped solid-state yellow laser generated by intracavity sum-frequency generation so far.

Focus on lasers and optics

Focus on lasers and optics

A 4.8-W M2 = 4.6 Continuous-Wave IntracavitySum-Frequency Diode-Pumped Solid-State Yellow Laser

A yellow continuous wave with beam quality M2 = 4.6 andoutput power of 4.8 W at 589 nm is generated by intracavitysum-frequency mixing of 1064 nm and 1319 nm radiations of a Nd:YAG laser.To achieve high beam quality at high power, thermally near-unstableflat–flat resonators with two-rod birefringence compensation aredesigned to obtain the large fundamental mode size inside the Nd:YAGrods and the same beam width inside the KTP crystal. The optimalintracavity power ratio of both 1064 nm and 1319 nm beams is alsoconsidered. The output power fluctuation of the yellow laser remainsless than 5% in four hours.