633-nm tunable external-cavity diode laser with an intracavity glass plateas the fine-tuning device

The application of beatwave Fabry-Perot interferometers (BFPIs) to nonlinea rity error calibration is limited by the short tuning range of the slave He -Ne laser. In this paper, a 633-nm tunable external-cavity diode laser (ECL ) is proposed as the slave laser of a BFPI. The ECL consists of an antirefl ection-coated quantum-well laser diode, a collimating lens, and a diffracti on grating in Littrow configuration. In addition, an intracavity glass plat e is adopted to provide cavity fine tuning, which makes the ECL more conven ient, as it is easier to align the light in the cavity. At an optical lengt h of 45 mm, a coarse-tuning range of 4 nm around 633 nm is obtained by rota ting the grating. It is also demonstrated that this ECL can operate in a si ngle-mode regime and can be continuously tuned over a frequency range of 1. 8 GHz by tilting the intracavity glass plate. (C) 2001 Society of Photo-Opt ical Instrumentation Engineers.