Patent ID: 8388609

Claim:
A system for photoaltering corneal stromal tissue to separate of the stromal tissue, the system comprising: a laser source operable to produce a primary pulsed beam having an irradiance greater than a threshold for optical breakdown of the stromal tissue; a first optical element configured to receive the primary pulsed beam and transmit a first secondary beam, the first secondary beam based on the primary pulsed beam and phase shifted from the primary pulsed beam by about a first quarter wavelength; a first polarizing beam splitter configured to reflect a first polarized beam and transmit a second polarized beam, the first and second polarized beams together based on the first secondary beam; a subsystem configured to produce a first transmission beam and a second transmission beam based on the first and second polarized beams, the first transmission beam angularly separated from the second transmission beam, the subsystem comprising: a second optical element configured to receive the first polarized beam and transmit a second secondary beam, the second secondary beam based on the first polarized beam and phase shifted from the first polarized beam by about a second quarter wavelength; a first mirror configured to reflect the second secondary beam to a second wave plate, the second wave plate further configured to transmit the first transmission beam; a third optical element configured to receive the second polarized beam and transmit a third secondary beam, the third secondary beam based on the second polarized beam and phase shifted from the second polarized beam by about a third quarter wavelength; and a second mirror configured to reflect the third secondary beam to a third wave plate, the third wave plate further configured to transmit the second transmission beam; a scanner operable to direct the first and second transmission beams to the material for plasma mediated photoablation of the stromal tissue; and a controller communicating with the scanner to control the direction of the transmission beams to create a separation of the stromal tissue based on a structured pattern of scan spots associated with the transmission beams.