THz waves are today used for Imaging (security) and Spectroscopy. The IPR in France recently demonstrated a new dual-frequency 780 nm Ti:Sa laser optimized for high spectral purity tunable CW-THz generation. Optimization of the dual –frequency laser has been based on real time and high-resolution instrument.
For dual-frequency laser, more than one laser peak need to be controlled. If a high resolution laser spectrum analyzer is used, one can control the spacing between the two peaks and their absolute wavelength. This capability is for instance useful for creation and tunability of dual-frequency laser to be used in sensing applications or in Terahertz generation. This has been used by the IPR in order to develop a dual-frequency 780 nm Ti:Sa laser optimized for high spectral purity tunable CW-THz generation. They used a real-time and high resolution spectrometer at different steps of the development of the laser to check the multi-mode, single-mode or dual-frequency operation and THz tunability of the laser.
Wavelength variations of a dual frequency laser
See article published by the IPR on “Dual-Frequency 780-nm Ti:Sa Laser for High Spectral Purity Tunable CW THz Generation”, IEEE PHOTONICS TECHNOLOGY LETTERS, VOL. 26, NO. 15, AUGUST 1, 2014.