Patent ID: 6853670

Claim:
A laser resonator comprising: a laser material for being excited by a light source to amplify optically a laser beam; a first telescope for magnifying the laser beam which has been made incident from said laser material and for reducing the laser beam which has been made incident from the opposite side to the side of said laser material; first reflecting means for reflecting the laser beam, which has been made incident from said first telescope in the direction opposite to the incident direction; a second telescope which is arranged in such a way as to face said first telescope with said laser material sandwiched between said first telescope and said second telescope and which serves to magnify the laser beam which has been reflected by said first reflected means to be reduced by said first telescope and to be amplified by said laser material to be made incident thereto and also serves to reduce the laser beam which has been made incident from the opposite side to the side of said laser material; and second reflecting means which is arranged in such a way as to face said first reflecting means with said laser material sandwiched between said first reflecting means and said second I reflecting means and which serves to reflect the laser beam, which has been made incident from said second telescope, in the opposite direction to the incident direction, wherein magnifications of said first and second telescopes are set such that a loss to a lower mode decreases and a loss to a higher mode increases in the resonator.