Synchronized Fiber Laser for High Resolution THz Spectroscopy
A new solution based on our femtosecond fiber laser in combination with the photomixing technique has been recently proposed by Gaël Mouret and his team at the Université du Littoral Cote d'Opale at the IRMMW-THz 2008 conference in Pasadena, CA.
The frequency spectrum of a pulse train emitted by the femtosecond laser consist of a comb of frequencies. The spacing between each line is determined by the repetition rate of the laser, which can be controlled by varying the cavity length. The frequency comb is then used like a ruler, to measure and stabilize the frequency of two cavity diode lasers.
Schematics of a Femtosecond Laser Frequency Comb
By locking two external cavity diode lasers, which operate near 780 nm, detuned from each other to the desired THz frequency, THz radiation between 50 GHz up to 3000 GHz can be synthesized. No other solution offers such a large tunability as this solid-state THz source.
Experimental Setup
