| 摘要 |
<p>A system and method for producing relatively square laser pulses derived from relatively Gaussian laser pulses. The system (10) comprises a phase conjugate laser system that comprises a laser oscillator (11), an amplifying medium (15) and a phase conjugate mirror (18) having a nonlinear medium confined at a predetermined pressure. The mirror (18) is adapted to truncate the front portion of an applied laser pulse. A plasma switch (12) is disposed between the laser oscillator (11) and the amplifying medium (15) that has a gas confined therein at a predetermined pressure. The plasma switch (12) and phase conjugate mirror (18) cooperate to truncate the laser pulse to produce a laser pulse having a relatively square shape. Controlling the pressures in the plasma switch (12) and phase conjugate mirror (18) provides a means of controlling the formation of square-shaped laser pulses. In addition, a delay line (16) may be employed in the system (10) that is controllable in length that assists in controlling the truncation of the pulse in the plasma switch (12). A method of forming a square laser pulse in accordance with the invention comprises the following steps. A laser pulse is propagated through a plasma switch (12), and the pressure therein is adjusted to truncate the rear portion of the laser pulse. The truncated laser pulse is then transmitted through a laser amplifier medium (15) to amplify the laser pulse. The amplified laser pulse is then reflected from a phase conjugate mirror (18). The pressure in the phase conjugate mirror (18) is adjusted to a predetermined pressure to truncate the front portion of the laser pulse, thus producing a relatively square output pulse. Additionally, the relative length of a delay line (16) disposed in the optical path may also be adjusted to assist in truncating the rear portion of the laser pulse.</p> |
