The disclosure provides a high-frequency-reproducibility laser frequency stabilization method and device based on multi-point acquisition of laser tube temperature. The laser frequency stabilization device includes: a frequency stabilization control circuit. The frequency stabilization control circuit includes a polarizing beam splitter, an optical power conversion circuit, an A/D conversion circuit, a temperature measuring circuit, a microprocessor, a D/A converter and a heating film driver. The polarizing beam splitter is disposed outside any one of laser transmitting holes. The optical power conversion circuit is disposed on reflection and refraction optical paths of the polarizing beam splitter. The optical power conversion circuit, the A/D conversion circuit, the microprocessor, the D/A converter, the heating film driver and a plurality of groups of heating films are sequentially in one-way connection. Temperature sensors, the temperature measuring circuit and the microprocessor are sequentially in one-way connection.

Provided is a light source apparatus and an electrode design for use in a discharge chamber of the light source apparatus. The discharge chamber is configured to hold a gas discharge medium configured to output a light beam. The light source apparatus include a pair of opposed electrodes configured to excite a gas medium to form a discharge plasma. At least one electrode of the pair of opposing electrodes may include recessed portions or hollowed-out portions at each end of the electrode, or at other suitable locations. The disclosed electrode structures improve uniformity of the erosion profile of the electrodes, significantly extending the lifespan of the discharge chamber by redistributing the discharge particle flux through the electrode with an optimized design of the electrode geometry, as the local discharge particle flux is reduced at the recessed portions.

Provided is a light source apparatus and an electrode design for use in a discharge chamber of the light source apparatus. The discharge chamber is configured to hold a gas discharge medium configured to output a light beam. The light source apparatus include a pair of opposed electrodes configured to excite a gas medium to form a discharge plasma. At least one electrode of the pair of opposing electrodes may include recessed portions or hollowed-out portions at each end of the electrode, or at other suitable locations. The disclosed electrode structures improve uniformity of the erosion profile of the electrodes, significantly extending the lifespan of the discharge chamber by redistributing the discharge particle flux through the electrode with an optimized design of the electrode geometry, as the local discharge particle flux is reduced at the recessed portions.

A laser device may include a laser resonator; a chamber arranged on an optical path of the laser resonator; a pair of electrodes arranged in the chamber; a power source applying a voltage to the electrodes; a storage unit storing a voltage value; and a control unit configured to set an application voltage value of the voltage applied to the electrodes as setting the application voltage value for outputting a pulse whose pulse number is equal to or larger than 1 and smaller than i based on the voltage command value and the voltage value stored in the storage unit, and setting the application voltage for outputting a pulse whose pulse number is equal to or larger than i and smaller than j based on the voltage command value and an offset value corresponding to the voltage command value, where i>1 and j>i.

A laser device may include a laser resonator; a chamber arranged on an optical path of the laser resonator; a pair of electrodes arranged in the chamber; a power source applying a voltage to the electrodes; a storage unit storing a voltage value; and a control unit configured to set an application voltage value of the voltage applied to the electrodes as setting the application voltage value for outputting a pulse whose pulse number is equal to or larger than 1 and smaller than i based on the voltage command value and the voltage value stored in the storage unit, and setting the application voltage for outputting a pulse whose pulse number is equal to or larger than i and smaller than j based on the voltage command value and an offset value corresponding to the voltage command value, where i>1 and j>i.

A laser apparatus according to an aspect of the present disclosure includes: a master oscillator; at least one amplifier disposed on an optical path of a first pulse laser beam output from the master oscillator; a sensor disposed on an optical path of a second pulse laser beam output from the at least one amplifier; and a laser controller. The laser controller causes the laser apparatus to perform burst oscillation based on a burst signal from an external device, and performs processing of controlling a beam parameter based on a sensor output signal obtained from the sensor in a burst duration, and processing of detecting self-oscillation light from the amplifier based on a sensor output signal obtained from the sensor in a burst stop duration.

A laser apparatus according to an aspect of the present disclosure includes: a master oscillator; at least one amplifier disposed on an optical path of a first pulse laser beam output from the master oscillator; a sensor disposed on an optical path of a second pulse laser beam output from the at least one amplifier; and a laser controller. The laser controller causes the laser apparatus to perform burst oscillation based on a burst signal from an external device, and performs processing of controlling a beam parameter based on a sensor output signal obtained from the sensor in a burst duration, and processing of detecting self-oscillation light from the amplifier based on a sensor output signal obtained from the sensor in a burst stop duration.

Disclosed is a laser system including a first laser and a second laser. The first laser includes a laser cavity, and a gas phase molecular gain medium disposed in the laser cavity, the gain medium having an absorption band. The second laser is a solid state laser configured to be continuously tunable, with respect to an emission wavelength of the second laser, over the absorption band of the gain medium, and the second laser is tuned to pump rotational vibrational transitions in the gain medium to achieve a rotational population inversion.

An exposure method includes reading data representing a relationship between a first parameter relating to an energy ratio between energy of first pulsed laser light having a first wavelength and energy of second pulsed laser light having a second wavelength longer than the first wavelength and a second parameter relating to a sidewall angle of a resist film that is the angle of a sidewall produced when the resist film is exposed to the first pulsed laser light and the second pulsed laser light, and determining a target value of the first parameter based on the data and a target value of the second parameter; and exposing the resist film to the first pulsed laser light and the second pulsed laser light by controlling a narrowed-line gas laser apparatus to output the first pulsed laser light and the second pulsed laser light based on the target value of the first parameter.

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.