A method of transplanting a cornea from a donor to a recipient is disclosed. An undercut is incised within stromal tissue of the donor cornea. Following formation of the undercut, the donor cornea is grafted onto a recipient. The undercut may be formed before or after the cornea is removed from the donor, and is preferably formed by photoaltering the stromal tissue using a laser. A sidecut may also be incised in the donor cornea, thereby forming a corneal flap, prior to grafting. In addition, a corneal section may be excised from the donor cornea using a trephine, a laser, or other appropriate surgical equipment.

A surgical laser system can include a laser engine to generate a laser beam of laser pulses, a scanning delivery system to direct the laser beam to a target region and to scan the laser beam along a scan-pattern in the target region, and a pupil system to modulate the laser beam. In addition, a method of adjusting a pupil of a laser beam can include: generating a laser beam of laser pulses with a laser engine, directing the laser beam to a target region with a scanning delivery system, scanning the laser beam along a scan-pattern in the target region with the scanning delivery system, and performing a modulation of the laser beam with an adjustable pupil system.

A medical laser using solely an electronic shutter circuit for controlling the laser output, without any mechanical shutter mechanism, is provided for use in clinical applications. The medical laser has several advantages compared to medical lasers with mechanical shutters. These advantages can be defined in terms of the speed of the electronic shutter, increased reliability, increased safety, smaller and less expense. The medical laser according to the invention will shut the laser down in less than 100 microseconds making it far superior to what would be possible with a typical mechanical shutter which would take at least 10 ms to disable the laser. Safety and reliability is a result of an electronic shutter circuit with at least two current sensors, at least two photodetectors and a set of one, two or three fast electronic safety switches.