An electrodeless laser-driven light source includes a laser that generates a CW sustaining light. A pump laser generates pump light. A Q-switched laser crystal receives the pump light generated by the pump laser and generates pulsed laser light at an output in response to the generated pump light. A first optical element projects the pulsed laser light along a first axis to a breakdown region in a gas-filled bulb comprising an ionizing gas. A second optical element projects the CW sustaining light along a second axis to a CW plasma region in the gas-filled bulb comprising the ionizing gas. A detector detects plasma light generated by a CW plasma and generates a detection signal at an output. A controller generates control signals that control the pump light to the Q-switched laser crystal so as to extinguish the pulsed laser light within a time delay after the detection signal exceeds a threshold level.

An electrodeless laser-driven light source includes a laser that generates a CW sustaining light. A pump laser generates pump light. A Q-switched laser crystal receives the pump light generated by the pump laser and generates pulsed laser light at an output in response to the generated pump light. A first optical element projects the pulsed laser light along a first axis to a breakdown region in a gas-filled bulb comprising an ionizing gas. A second optical element projects the CW sustaining light along a second axis to a CW plasma region in the gas-filled bulb comprising the ionizing gas. A detector detects plasma light generated by a CW plasma and generates a detection signal at an output. A controller generates control signals that control the pump light to the Q-switched laser crystal so as to extinguish the pulsed laser light within a time delay after the detection signal exceeds a threshold level.

A radiation source apparatus comprising: a container for being pressurised with a gaseous medium in which plasma which emits plasma emitted radiation is generated following excitation of the gaseous medium by a driving radiation, wherein said container is operable substantially to remove radiation with a wavelength of 10-400 nm from said plasma emitted radiation before said plasma emitted radiation exits said container as output radiation. In an embodiment the container comprises: an inlet radiation transmitting element operable to transmit said driving radiation from outside said container to inside said container, and an outlet radiation transmitting element operable to transmit at least some of said plasma emitted radiation from inside said container to outside said container as output radiation; wherein at least one of said inlet and outlet radiation transmitting elements comprises a plane parallel plate.

A radiation source apparatus comprising: a container for being pressurised with a gaseous medium in which plasma which emits plasma emitted radiation is generated following excitation of the gaseous medium by a driving radiation, wherein said container is operable substantially to remove radiation with a wavelength of 10-400 nm from said plasma emitted radiation before said plasma emitted radiation exits said container as output radiation. In an embodiment the container comprises: an inlet radiation transmitting element operable to transmit said driving radiation from outside said container to inside said container, and an outlet radiation transmitting element operable to transmit at least some of said plasma emitted radiation from inside said container to outside said container as output radiation; wherein at least one of said inlet and outlet radiation transmitting elements comprises a plane parallel plate.

During a normal operation,alternating drive voltage to be applied between a pair of electrodes provided to face an outer surface of a bottom part of a gas discharge light emitting tube is switched to a voltage value V2 lower than a voltage value V1 at the time of starting lighting. Further, the alternating drive voltage to be applied during the normal discharge operation is intermittently applied in a predetermined cycle and duty ratio to enable adjustment of light emission intensity.

A gas discharge device includes a thin glass tube filled with a discharge gas; a pair of first and second long electrodes extending toward either side along a longitudinal direction with a discharge gap interposed therebetween are provided outside of a back side flat surface of a thin glass tube; and a ultraviolet phosphor layer formed on an inner surface at the back side flat surface, the thin glass tube filled with a discharge gas having a front side flat surface and the back side flat surface facing each other on a transverse section, wherein, starting with trigger discharge that is initially generated in the discharge gap as a result of a voltage increase when a voltage with a sine waveform or an inclined waveform is applied between both electrodes, the discharge gradually extends so as to move in the longitudinal direction of the electrodes. Ultraviolet light having high luminous efficiency and emission intensity is obtained from a front side surface of the thin glass tube by driving the device with a sine-wave AC voltage.

A gas discharge device includes a thin glass tube filled with a discharge gas; a pair of first and second long electrodes extending toward either side along a longitudinal direction with a discharge gap interposed therebetween are provided outside of a back side flat surface of a thin glass tube; and a ultraviolet phosphor layer formed on an inner surface at the back side flat surface, the thin glass tube filled with a discharge gas having a front side flat surface and the back side flat surface facing each other on a transverse section, wherein, starting with trigger discharge that is initially generated in the discharge gap as a result of a voltage increase when a voltage with a sine waveform or an inclined waveform is applied between both electrodes, the discharge gradually extends so as to move in the longitudinal direction of the electrodes. Ultraviolet light having high luminous efficiency and emission intensity is obtained from a front side surface of the thin glass tube by driving the device with a sine-wave AC voltage.

The excimer lamp includes: a discharge container having a substantially quadrangular shape with a cross section, the discharge container having a pair of flat walls extending in a longitudinal direction and a pair of side walls connecting the flat walls; a pair of external electrodes facing each other disposed on outer surfaces of the pair of flat walls, respectively; a first internal electrode disposed inside the discharge container so as to extend toward inner surfaces of the pair of flat walls; and a second internal electrode disposed inside the discharge container at a position spaced apart from the first internal electrode in the longitudinal direction so as to extend toward the inner surfaces of the pair of flat walls. The first internal electrode and the second internal electrode are respectively disposed at positions between end parts and central parts of the external electrodes in the longitudinal direction.

An electrodeless laser-driven light source includes a laser source that generates a CW sustaining light and a pump laser that generates a pump. An optical beam combiner combines the CW sustaining light and the pump such that the CW sustaining light and the pump propagate co-linearly. A Q-switched laser crystal generates pulsed light in response to the pump. A gas-filled bulb is configured such that the pulsed light ignites a pulse plasma in a breakdown region of the gas bulb and the sustaining light sustains a CW plasma in a CW plasma region of the gas bulb, thereby emitting a high brightness light from the gas bulb, where the gas-filled bulb is positioned between the output of the pump laser and the pump input of the Q-switched laser crystal such that the CW plasma absorbs the pump light quenching the pulsed light generated by the Q-switched laser crystal.

An electrodeless laser-driven light source includes a laser source that generates a CW sustaining light and a pump laser that generates a pump. An optical beam combiner combines the CW sustaining light and the pump such that the CW sustaining light and the pump propagate co-linearly. A Q-switched laser crystal generates pulsed light in response to the pump. A gas-filled bulb is configured such that the pulsed light ignites a pulse plasma in a breakdown region of the gas bulb and the sustaining light sustains a CW plasma in a CW plasma region of the gas bulb, thereby emitting a high brightness light from the gas bulb, where the gas-filled bulb is positioned between the output of the pump laser and the pump input of the Q-switched laser crystal such that the CW plasma absorbs the pump light quenching the pulsed light generated by the Q-switched laser crystal.