High-powered green light generation by intracavity frequency doubling using grating feedback optics

Area of Science:

• Optics and Photonics
• Laser Physics
• Materials Science

Background:

• Multilongitudinal-mode laser diodes often exhibit broad spectral bandwidths.
• Nd:YVO(4) lasers are crucial for various optical applications.
• Efficient frequency doubling requires precise wavelength matching and narrow spectral output.

Purpose of the Study:

• To narrow the spectral bandwidth of a multilongitudinal-mode laser diode using grating feedback optics.
• To tune the laser diode's wavelength to the peak absorption of Nd:YVO(4).
• To investigate the efficiency and noise characteristics of intracavity frequency-doubled green light generation.

Main Methods:

• Utilized grating feedback optics to control the spectral bandwidth of a laser diode.
• Employed intracavity frequency doubling with a KTiOPO(4) crystal for green light generation.
• Measured relative intensity noise (RIN) of the generated green light.

Main Results:

• Achieved a spectral bandwidth of less than 0.2 nm for the laser diode.
• Efficiently generated 31 mW of continuous green light by frequency doubling.
• Obtained a relative intensity noise of less than -140 dB/Hz for frequencies above 2 MHz.

Conclusions:

• Grating feedback optics effectively narrows laser diode bandwidth and tunes wavelength for efficient Nd:YVO(4) laser pumping.
• Intracavity frequency doubling provides a viable method for generating low-noise green laser light.
• The noise characteristics are comparable to systems using single-longitudinal-mode laser diodes.