Rapidly tuneable external cavity diode laser

External cavity diode lasers are often tuned by letting a piezoelectric actuator move the grating, thereby changing the length of the cavity. In order to reach higher repeatability and tuning speeds one can incorporate an electro-optical crystal (EOC) into the cavity. The index of refraction of the EOC can be changed by applying an electric field across it, thereby accurately changing the effective optical length of the cavity. We have designed and built a laser using the ideas above for use in coherent transient spectroscopy on thulium doped inorganic crystals at 793 nm.