The invention relates to plasma light sources with a continuous optical discharge (COD). The light source contains a gas filled chamber with a region of radiating plasma sustained by a focused beam of a CW laser. A density of gas particles in the chamber is less than 90.Math.10.sup.19 cm.sup.3 and a temperature of the chamber is in a range from 600 to 900 K or optionally higher. Preferably the density of gas particles is as low as possible and the temperature of the inner surface of the chamber at operation is as high as possible under providing a gas pressure in the chamber of about 50 bar or more. The technical result of the invention consists in providing COD sustaining conditions, which are optimal for achieving high stability and high brightness of the radiating plasma, in the creation on this basis of broadband light sources with ultra-high brightness and stability.

The invention relates to plasma light sources with a continuous optical discharge (COD). The light source contains a gas filled chamber with a region of radiating plasma sustained by a focused beam of a CW laser. A density of gas particles in the chamber is less than 90.Math.10.sup.19 cm.sup.3 and a temperature of the chamber is in a range from 600 to 900 K or optionally higher. Preferably the density of gas particles is as low as possible and the temperature of the inner surface of the chamber at operation is as high as possible under providing a gas pressure in the chamber of about 50 bar or more. The technical result of the invention consists in providing COD sustaining conditions, which are optimal for achieving high stability and high brightness of the radiating plasma, in the creation on this basis of broadband light sources with ultra-high brightness and stability.

A double-ended high intensity discharge lamp includes a luminous tube and reflective layer covering at a reflective portion provided on at least a portion of aid luminous tube for reflecting light emitted from an illuminator supported in the luminous tube towards the reflective portion to project towards another opposing side of the luminous tube.

Provided are a plasma light source capable of solving a problem occurring when an arc discharge lamp is used and an inspection apparatus capable of providing uniform and high-brightness plasma light. The plasma light source includes a pulse laser generator configured to generate a pulse laser beam, a continuous wave (CW) laser generator configured to generate an infrared ray (IR) CW laser beam, a first dichroic mirror configured to transmit or reflect the pulse laser beam and reflect or transmit the IR CW laser beam, a chamber configured to receive the pulse laser beam to ignite plasma and the IR CW laser beam to maintain the plasma in an ignited state, and discharge plasma light generated by the plasma, and a second dichroic mirror configured to transmit the pulse laser beam and the IR CW laser beam and reflect the plasma light.

There is provided a calcium fluoride optical member formed from monocrystalline calcium fluoride and having a tubular shape. A {110} crystal plane or a {111} crystal plane of the monocrystalline calcium fluoride is orthogonal to a center axis of the tube.