A control method for a line narrowed gas laser apparatus is a control method for a line narrowed gas laser apparatus configured to emit a pulse laser beam including a first wavelength component and a second wavelength component. The apparatus includes a laser chamber including a pair of electrodes, an optical resonator including an adjustment mechanism configured to adjust a parameter of an energy ratio of the first and second wavelength components, and a processor in which relation data indicating a relation of the parameter of the energy ratio with a control parameter of the adjustment mechanism is stored. The control method includes receiving a command value of the parameter of the energy ratio from an external device, and acquiring, based on the relation data, a value of the control parameter corresponding to the command value and controlling the adjustment mechanism based on the value of the control parameter.

A line narrowing device includes a first prism; first and second gratings arranged on the optical path of the light beam having passed through the first prism at positions different in a direction of grooves of either the first grating or the second grating; a beam adjustment optical system arranged on the optical path of the light beam between the first prism and at least one grating of the first and second gratings, and causing a first portion of the light beam to be incident on the first grating and causing a second portion of the light beam to be incident on the second grating; a first actuator adjusting an incident angle of the first portion on the first grating; a second actuator adjusting an incident angle of the second portion on the second grating; and a third actuator adjusting an energy ratio of the first and second portions.

A narrowed-line gas laser apparatus includes a laser chamber that accommodates a pair of electrodes disposed so as to face each other, an output coupling mirror, and a line narrowing apparatus that forms an optical resonator along with the output coupling mirror, the line narrowing apparatus including an optical system having a first region and a second region on which a first portion and a second portion of a light beam that exits out of the laser chamber are incident, the first and second portions passing through different positions in a direction in which the pair of electrodes face each other, the optical system being configured to suppress an increase in the distance between the optical path axis of the first portion and the optical path axis of the second portion.

A sensor degradation evaluation method according to an aspect of the present disclosure includes an evaluation step of evaluating degradation of at least one of a sensor for coarse measurement that receives interference fringes produced by a spectrometer for coarse measurement and a sensor for fine measurement that receives interference fringes produced by a spectrometer for fine measurement, and the evaluation step includes causing a plurality of kinds of laser light having wavelengths different from one another to be sequentially incident on the spectrometer for coarse measurement and the spectrometer for fine measurement and acquiring a coarse-measurement wavelength and a fine-measurement wavelength on a wavelength basis from a plurality of the received interference fringes, acquiring a degradation parameter on a wavelength basis from the coarse-measurement wavelength and the fine-measurement wavelength on a wavelength basis, and comparing the degradation parameter on a wavelength basis with a threshold.

An exposure system according to an aspect of the present disclosure includes a laser apparatus that outputs pulsed laser light, an illuminating optical system that guides the pulsed laser light to a reticle, a reticle stage, and a processor that controls the output of the pulsed laser light from the laser apparatus and the movement of the reticle performed by the reticle stage. The reticle has a first region where a first pattern is disposed and a second region where a second pattern is disposed, and the first and second regions are each a region continuous in a scan width direction perpendicular to a scan direction of the pulsed laser light, with the first and second regions arranged side by side in the scan direction. The processor controls the laser apparatus to output the pulsed laser light according to each of the first and second regions by changing the values of control parameters of the pulsed laser light in accordance with each of the first and second regions.

A diffractive optical element, such as a plasma grating, can be made by directing two laser beams so that they overlap in a nonlinear material to form an interference pattern in the nonlinear material. The interference pattern can modify the index of refraction in the nonlinear material to produce the diffractive optical element. A chirped pulse amplification system can stretch, amplify, and then compress a laser pulse, and the plasma grating can be used to compress the laser pulse since the plasma optic can withstand the high light intensity of the compressed pulse.

An internal laser component of an optical device comprises: a waveguide that defines a guided mode of a first optical wave characterized by a first propagation constant associated with a first effective refractive index. An optical antenna grating comprises: a waveguide that defines a guided mode of a second optical wave characterized by a second propagation constant associated with a second effective refractive index, and a grating structure configured to emit a portion of the second optical wave in a selected direction. The internal laser component and the optical antenna grating are configured to provide a relationship between the first effective refractive index and the second effective refractive index such that the selected direction is substantially insensitive to a change in a temperature of a thermal environment in which the internal laser component and the optical antenna grating are thermally coupled.

In some general aspects, a light beam control apparatus includes: a spectral feature actuator associated with a set of different states, each state configured to cause an optical apparatus to generate one or more pulses of a light beam at a discrete value of a spectral feature of the light beam; and a controller in communication with the spectral feature actuator. The controller includes: an actuator drive module configured to cause the spectral feature actuator to transition among the set of different states according to a control waveform; a waveform module configured to compute the control waveform for the spectral feature actuator that governs the transition among the set of discrete values; and a predictive module configured to receive one or more sensed aspects of the spectral feature actuator and instruct the waveform module to adjust the control waveform based on the received sensed aspects.

A measurement device includes: an optical gain unit for generating and amplifying light; a transmission optical band variation unit for selecting a specific optical frequency band from the light generated by the optical gain unit, and varying the selected specific optical frequency band to transmit light; a resonant optical frequency variation unit for performing a frequency variation so that multiple resonant optical frequency orders within the specific optical frequency band vary over a variation range narrower than intervals between the respective orders; resonance induction units forming an optical resonance unit which includes the optical gain unit, the transmission optical band variation unit, and the resonant optical frequency variation unit and causes selective oscillation of light having a specific resonant optical frequency within a specific transmission optical band; and a control signal unit for varying each of the transmission optical band variation unit and the resonant optical frequency variation unit.

A laser chamber apparatus may include a pipe, an inner electrode extending along a longitudinal direction of the pipe and disposed in a through hole in the pipe, an outer electrode including a contact plate extending along the longitudinal direction of the pipe and being in contact with an outer circumferential surface of the pipe and a ladder section formed of bar members each having one end connected to the contact plate and juxtaposed along a longitudinal direction of the contact plate, and a leaf spring extending along the longitudinal direction of the pipe and configured to press the outer electrode against the pipe. The leaf spring may include leaf spring pieces separated by slits, and the leaf spring pieces may each include a bent section bent along the edge and are configured to press the bar members in a position shifted from the bent sections toward the edge.