Laser working apparatus, laser working method, method for producing ink jet recording head utilizing such laser working apparatus or method, and ink jet recording head formed by such producing method

A laser working apparatus for effecting optical ablation working by irradiating a work article with a laser light with a pulse emission time not exceeding 1 picosecond from a laser oscillator capable of continuos emission of a light pulse of a large energy density in space and in time, with the pulse emission time not exceeding 1 picosecond, the laser working apparatus for effecting optical ablation working comprising:

• a light intercepting control means, disposed in a light path of laser light with the pulse emission time not exceeding 1 picosecond from the laser oscillator to the work article, for selecting a state where the laser light with the pulse emission time not exceeding 1 picosecond can be irradiated to irradiate the work article or a light intercepting state where the laser light with the pulse emission time not exceeding 1 picosecond cannot be irradiated to the work article,
• wherein said light intercepting control means is heated by receiving irradiation of laser light with the pulse emission time not exceeding 1 picosecond at the light intercepting state,
• wherein the laser light, irradiating to and absorbed by said light intercepting control means, with the pulse emission time not exceeding 1 picosecond does not reach an ablation threshold value of energy density at which the work article is worked.