| 摘要 |
PURPOSE:To obtain an excimer laser characterized by high stability in wavelength of laser light by comparing the intensity of incident laser light which is inputted into a laser-light absorbing cell with the intensity of emitted transmitting laser light, and imparting a control signal where difference between both intensities become the largest value to a wavelength changing means. CONSTITUTION:A part of incident laser light which is reflected from a beam splitter 4 and laser light which is transmitted through the beam splitter 4, inputted into an absorbing cell 2 and transmitted through oxygen gas are inputted into photodiodes 2 and 3. The signals corresponding to the intensities of the incident laser lights are outputted and transferred into a wavelength controller 17. In the wavelength controller 17, the output value of the photodiode 2 is divided by the output value of the photodiode 3. A control signal where the divided value becomes the maximum value is outputted into a wavelength changing means. Here, the laser incident angle at an elaton 13 is adjusted, and the value in a transmitting wavelength band is changed. Thus the oscillating wavelength of the laser light is changed. Therefore, the wavelength of the emitted laser light 14 is tuned to the absorbing line of the oxygen gas. |
