Characterisation of an extended cavity violet diode laser

We describe the construction and characterisation of a GaN violet laser diode in a compact, extended cavity geometry. Up to 3.5 mW of single frequency power at 392 nm is generated which is continuously tuneable over 6 GHz and coarsely tuneable over 2.7 nm. We place an upper limit on the linewidth of 5 MHz. The performance of the violet diode laser is compared to that of visible laser diodes in our extended cavity geometry. Possible spectroscopic applications are discussed. (C) 2000 Elsevier Science B.V. All rights reserved.