Dual-wavelength, continuous-wave Yb:YAG laser for high-resolution photothermal common-path interferometry

Area of Science:

• Laser physics
• Optical engineering
• Materials science

Background:

• Photothermal common-path interferometry requires precise light sources for accurate material property measurements.
• Simultaneous dual-wavelength lasers offer unique advantages for probing both linear and nonlinear absorption characteristics.

Purpose of the Study:

• To design and demonstrate a continuous-wave (CW) intracavity frequency-doubled Ytterbium-doped Yttrium Aluminum Garnet (Yb:YAG) laser.
• To achieve simultaneous output at 1030 nm and 515 nm for advanced absorption spectroscopy applications.

Main Methods:

• Utilized a Z-shape laser cavity design for optimal beam focusing.
• Incorporated a Lithium Triborate (LBO) crystal for efficient second-harmonic generation (SHG).
• Optimized frequency conversion parameters and cavity configurations for diode-pumped CW SHG laser performance.

Main Results:

• Successfully generated simultaneous CW output at 1030 nm and 515 nm.
• Achieved a maximum output power of 12.4 W at 1030 nm and 5.4 W at 515 nm.
• Demonstrated the laser's suitability for photothermal common-path interferometry.

Conclusions:

• The developed Yb:YAG laser system provides a versatile dual-wavelength source for material characterization.
• The design enables precise measurement of linear and nonlinear absorption profiles in dielectric media and coatings.
• This technology advances optical diagnostics for visible and infrared light applications.