Laser apparatus for generating vacuum ultraviolet narrow-band laser beams

A laser apparatus comprising:

• a laser oscillator for generating a vacuum ultraviolet laser beam having a narrowed bandwidth in a vacuum ultraviolet band to output the vacuum ultraviolet laser beam;
• a reference light source for generating a reference beam having a spectral distribution in the vacuum ultraviolet band to output the reference beam, said reference light source including a housing formed with a hallow portion for generating vacuum ultraviolet light, a resonant unit, sandwiching said housing, for resonating the vacuum ultraviolet light and amplifying the resonated vacuum ultraviolet light so as to generate a laser beam having a bandwidth which is not narrowed, as the reference beam, supplying means for supplying a medium from which the vacuum ultraviolet light is generated into said hallow portion, an exhausting unit for exhausting said medium from said hallow portion, and a pressure meter for measuring pressure in said hallow portion;
• a wavelength meter for measuring a central wavelength of the vacuum ultraviolet laser beam by using at least one emission light contained in the reference beam as a reference;
• and
• control means for controlling said supplying means on the basis of the pressure in said hallow portion measured by said pressure meter to adjust the pressure of said hallow portion to a predetermined value and controlling said laser oscillator on the basis of the central wavelength of the vacuum ultraviolet laser beam measured by said wavelength meter to adjust the central wavelength of the vacuum ultraviolet laser beam to a target wavelength.

A laser apparatus comprising:

• a laser oscillator for generating a vacuum ultraviolet laser beam having a narrowed bandwidth in a vacuum ultraviolet band to output the vacuum ultraviolet laser beam;
• a reference light source for generating a reference beam having a spectral distribution in the vacuum ultraviolet band to output the reference beam, said reference light source including a housing formed with a hallow portion for generating vacuum ultraviolet light, a resonant unit, sandwiching said housing, for resonating the vacuum ultraviolet light and amplifying the resonated vacuum ultraviolet light so as to generate a laser beam having a bandwidth which is not narrowed, as the reference beam, supplying means for supplying a medium from which the vacuum ultraviolet light is generated into said hallow portion, an exhausting unit for exhausting said medium from said hallow portion, a temperature meter for measuring a temperature in said hallow portion, and cooling means for cooling said housing;
• a wavelength meter for measuring a central wavelength of the vacuum ultraviolet laser beam by using at least one emission light contained in the reference beam as a reference;
• and
• control means for controlling said cooling means on the basis of the temperature measured by said temperature meter to adjust the temperature of said housing to a predetermined value and controlling said laser oscillator on the basis of the central wavelength of the vacuum ultraviolet laser beam measured by said wavelength meter to adjust the central wavelength of the vacuum ultraviolet laser beam to a target wavelength.

A laser apparatus comprising:

• a laser oscillator for generating a vacuum ultraviolet laser beam having a narrowed bandwidth in a vacuum ultraviolet band to output the vacuum ultraviolet laser beam;
• a reference light source for generating a reference beam having a spectral distribution in the vacuum ultraviolet band to output the reference beam, said reference light source including a housing formed with a hallow portion for generating vacuum ultraviolet light as the reference beam, supplying means for supplying a medium from which the vacuum ultraviolet light is generated into said hallow portion, an exhausting unit for exhausting said medium from said hallow portion, and a pressure meter for measuring pressure in said hallow portion;
• a wavelength meter for measuring a central wavelength of the vacuum ultraviolet laser beam by using at least one emission light contained in the reference beam as a reference;
• and
• control means for controlling said supplying means on the basis of the pressure in said hallow portion measured by said pressure meter to adjust the pressure of said hallow portion to a predetermined value and controlling said laser oscillator on the basis of the central wavelength of the vacuum ultraviolet laser beam measured by said wavelength meter to adjust the central wavelength of the vacuum ultraviolet laser beam to a target wavelength.

A laser apparatus comprising:

• a laser oscillator for generating a vacuum ultraviolet laser beam having a narrowed bandwidth in a vacuum ultraviolet band to output the vacuum ultraviolet laser beam;
• a reference light source for generating a reference beam having a spectral distribution in the vacuum ultraviolet band to output the reference beam, said reference light source including a housing formed with a hallow portion for generating vacuum ultraviolet light as the reference beam, supplying means for supplying a medium from which the vacuum ultraviolet light is generated into said hallow portion, an exhausting unit for exhausting said medium from said hallow portion, a temperature meter for measuring temperature in said hallow portion, and cooling means for cooling said housing;
• a wavelength meter for measuring a central wavelength of the vacuum ultraviolet laser beam by using at least one emission light contained in the reference beam as a reference;
• and
• control means for controlling said cooling means on the basis of the temperature measured by said temperature meter to adjust the temperature of said housing to a predetermined value and controlling said laser oscillator on the basis of the central wavelength of the vacuum ultraviolet laser beam measured by said wavelength meter to adjust the central wavelength of the vacuum ultraviolet laser beam to a target wavelength.