Patent ID: 8766137

Claim:
A laser processing apparatus comprising: a chuck table for holding a workpiece; and pulsed laser beam applying means for applying a pulsed laser beam to said workpiece held on said chuck table, said pulsed laser beam applying means including a pulsed laser beam oscillator for oscillating a pulsed laser beam of linearly polarized light, focusing means for focusing said pulsed laser beam oscillated by said pulsed laser beam oscillator and applying said pulsed laser beam focused to said workpiece held on said chuck table, and optical transmitting means for transmitting said pulsed laser beam oscillated by said pulsed laser beam oscillator to said focusing means, said optical transmitting means including wavelength band expanding means for expanding the wavelength band of said pulsed laser beam oscillated by said pulsed laser beam oscillator, pulse width expanding means for expanding the pulse width of said pulsed laser beam whose wavelength band has been expanded by said wavelength band expanding means, a focusing lens for focusing said pulsed laser beam whose pulse width has been expanded by said pulse width expanding means, an optical fiber for transmitting said pulsed laser beam focused by said focusing lens, a collimating lens for collimating said pulsed laser beam transmitted by said optical fiber, and pulse width compressing means for compressing the pulse width of said pulsed laser beam collimated by said collimating lens to restore the original pulse width and next transmitting said pulsed laser beam whose pulse width has been restored to said focusing means.