US 2010/0135341 A1 · Multiple Output Repetitively Pulsed Laser

Abstract

A continuously pumped, mode-locked laser is disclosed, which includes a cavity dumper that can remove a constant fraction of the light from the cavity at every 1/f period of time, independent of the time at which the first pulse in a train is initiated. The cavity dumper includes a modulator and two output arms, denoted as a primary output arm and a secondary output arm. When a user desires a train of pulses, the pulses are directed to the primary output arm. Between trains of pulses, when no pulse is desired by the user, the pulses are directed to the secondary output arm, which terminates in an absorber or at a secondary optical system. In this manner, the energy contained in each output pulse is essentially constant, from pulse-to-pulse and from train-to-train. This may overcome the disadvantage of many lasers that have a single output arm, in which the first pulse in a train may have an energy that depends on the length of the inactive period that immediately precedes the train.

Claims20

Dependent claims

A method of generating a laser output, comprising:

amplifying a first laser pulse within a cavity of a laser to establish a second laser pulse propagating along a path within the cavity in a first direction;
directing a first fraction of the second laser pulse into a first output arm, wherein a second fraction of the second laser pulse continues to propagate along the path in the first direction;
amplifying the second fraction of the second laser pulse within the cavity to establish a third laser pulse propagating along the path within the cavity in a second direction opposite the first direction;
directing a third fraction of the third laser pulse into a second output arm, wherein a fourth fraction of the third laser pulse continues to propagate along the path in the second direction;
amplifying the fourth fraction of the third laser pulse within the cavity to establish a fourth laser pulse within the cavity;
and
extracting the third fraction of the third laser pulse from the second output arm to provide the laser output.

4 more elements

A method of generating output pulses from a laser having a cavity bounded by a first mirror and a second mirror and containing a circulating intracavity pulse, comprising:

repeating for a predetermined number of cavity round-trips the sequence of:
reflecting the intracavity pulse from the first mirror;
retaining the intracavity pulse in the cavity with the cavity dumper;
reflecting the intracavity pulse from the second mirror;
and
retaining the intracavity pulse in the cavity with the cavity dumper;
reflecting the intracavity pulse from the first mirror;
directing a fraction of the intracavity pulse into a first output arm with a cavity dumper to form a first output pulse;
retaining a fraction of the intracavity pulse in the cavity;
reflecting the intracavity pulse from the second mirror;
retaining the intracavity pulse in the cavity with the cavity dumper;
repeating for the predetermined number of cavity round-trips the sequence of:
reflecting the intracavity pulse from the first mirror;
retaining the intracavity pulse in the cavity with the cavity dumper;
reflecting the intracavity pulse from the second mirror;
and
retaining the intracavity pulse in the cavity with the cavity dumper;
reflecting the intracavity pulse from the first mirror;
retaining the intracavity pulse in the cavity with the cavity dumper;
reflecting the intracavity pulse from the second mirror;
directing a fraction of the intracavity pulse into a second output arm with a cavity dumper to form a second output pulse;
and
retaining a fraction of the intracavity pulse in the cavity.

20 more elements

A method of generating output pulses from a laser having a cavity bounded by a first mirror and a second mirror and containing a circulating intracavity pulse, comprising:

repeating for a predetermined number of cavity round-trips the sequence of:
reflecting the intracavity pulse from the first mirror;
retaining the intracavity pulse in the cavity with a cavity dumper;
reflecting the intracavity pulse from the second mirror;
and
retaining the intracavity pulse in the cavity with the cavity dumper;
reflecting the intracavity pulse from the first mirror;
directing the intracavity pulse to the cavity dumper, the intracavity pulse having a total power at incidence upon the cavity dumper;
directing with the cavity dumper a first output percentage of the intracavity pulse into a first output arm to form a first output laser pulse;
retaining a first retention percentage of the intracavity pulse in the cavity;
reflecting the intracavity pulse from the second mirror;
directing with the cavity dumper a second output percentage of the intracavity pulse into a second output arm to form a second output laser pulse;
and
retaining a second retention percentage of the intracavity pulse in the cavity;
wherein the first output percentage is a desired output divided by the total power;
wherein the first retention percentage is 100% minus the first output percentage;
wherein the second output percentage is a cavity dumping ratio minus the first output percentage;
wherein the second retention percentage is 100% minus the cavity dumping ratio;
wherein the cavity comprises a cavity dumping repetition rate;
wherein the cavity has a characteristic profile of output pulse energy versus cavity dumping repetition rate, the characteristic profile including a first peak for the cavity dumping ratio;
and
wherein the cavity dumping repetition rate is away from the first peak.

19 more elements

A laser, comprising:

a cavity for containing intracavity light in a first direction and a second direction opposite the first direction;
a cavity dumper disposed in the cavity for selectively diverting intracavity light into either or neither of a first output arm or a second output arm, comprising a first polarizer having a first pass axis, a second polarizer having a second pass axis, and a modulator disposed in the laser cavity between the first and second polarizers;
and
a modulator controller for selectively rotating the polarization of intracavity light traveling in the first direction away from the first pass axis so that intracavity light traveling in the first direction reflects off the first polarizer to form the first output arm, and for selectively rotating the polarization of intracavity light traveling in the second direction away from the second pass axis so that intracavity light traveling in the second direction reflects off the second polarizer to form the second output arm;
wherein the cavity comprises a cavity dumping repetition rate and a cavity dumping ratio;
wherein the cavity has a characteristic profile of output pulse energy versus cavity dumping repetition rate, the characteristic profile including a first peak for the cavity dumping ratio;
and
wherein the cavity dumping repetition rate is away from the first peak.

5 more elements

Dependencies are inferred from the claim text.

Multiple Output Repetitively Pulsed Laser

Life of this patent

Multiple Output Repetitively Pulsed Laser

Life of this patent

Abstract

Claims20