Wavelength system for an excimer laser

摘要

A wavelength system for measuring and controlling the wavelength of a narrowband laser. The system includes a wavemeter for measuring incremental changes in wavelength and an atomic wavelength reference for calibrating the wavemeter. The atomic wavelength reference includes a vapor cell for providing a vapor having at least one absorption line near a desired operating wavelength. The system includes a wavelength tuning device with a tuning range sufficient to tune the laser to operate at the wavelength of the absorption line in order to calibrate the wavemeter. In a preferred embodiment, the laser is an ArF laser, and the vapor is platinum and the absorption line is either 193,224.3 pm or 193,436.9. Improvements over prior art devices include an improved etalon having a support flange to provide a low stress three-point hanging support for the etalon without use of elastomers.