Pulse laser resonator
AssigneePowerlase Limited
InventorsJason Palmer, David R. Klug, Ian P. Mercer, Daniel A. Allwood
Life of this patent
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Abstract
A laser is disclosed which includes a gain medium, a switch element, and a pulse controller. In one embodiment laser light of differing polarizations pass along respective paths and a pulsed laser output is generated via an electro-optical element. In another embodiment light of differing polarizations passes in differing directions through a cyclical path. The invention can make use of a prism-shaped polarizer having a polarization selection face and two further faces. Yet further initial pulses can be controlled to reduce energy, for example by progressively increasing the period or amplitude of successive pulses. As a result an efficient and high power laser apparatus is realized.
Claims25
A laser cavity for generating a pulsed laser output, comprising:
- a gain medium including a light transmission axis;
- at least one optical element disposed on one side of the gain medium to return laser light emitted from the one side of the gain medium back through the gain medium;
- a polarization selective element disposed on the light transmission axis to the other side of the gain medium;
- at least one further optical element arranged to define a cyclic optical path from the polarization selective element along which laser light is in use directed in one of the two directions depending on the polarization of the laser light;
- and
- at least one electro-optical element disposed in the optical path and being operable to switch the polarity of the laser light transmitted therethrough such as to generate a pulsed laser output;
- wherein the at least one further optical element comprises first and second further optical elements, with the first further optical element reflecting laser light to or from the second optical surface of the polarizer and the second further optical element reflecting laser light to or from the first optical surface of the polarizer;
- and
- wherein the at least one electro-optical element is disposed between the first and second further optical elements.
A pulsed laser comprising:
- a laser cavity;
- a laser gain medium within said laser cavity;
- an optical switch element operable to change a light loss level of said laser cavity and laser gain medium between a first loss state in which lasing is inhibited and second loss state in which lasing is not inhibited such that a laser pulse is generated;
- and
- a pulse controller operable to provide a control signal to said optical switch element to control repeated switching between said first loss state and said second loss state to trigger generation of a stream of laser pulses;
- wherein upon initiation of generation of laser pulses, said pulse controller generates control signals that progressively increase a period for which said laser cavity and laser gain medium are in said second loss state towards a steady state second loss period such that laser pulse energy at startup is reduced compared to if said steady state second loss period was used immediately upon startup.
A method of operating a pulsed laser having a laser cavity, a laser gain medium within said laser cavity, an optical switch element operable to change a light loss level of said laser cavity and laser gain medium between a first loss state in which lasing is inhibited and second loss state in which lasing is not inhibited such that a laser pulse is generated, and a pulse controller operable to provide a control signal to said optical switch element to control repeated switching between said first loss state and said second loss state to trigger generation of a stream of laser pulses;
- said method comprising the step of:
- upon initiation of generation of laser pulses, generating control signals that progressively increase a period for which said laser cavity and laser gain medium are in said second loss state towards a steady state second loss period such that laser pulse energy at startup is reduced compared to if said steady state second loss period was used immediately upon startup.
A pulsed laser comprising:
- a laser cavity;
- a laser gain medium within said laser cavity;
- an electro-optic switch element operable to change a light loss level of said laser cavity and laser gain medium between a first loss state in which lasing is inhibited and second loss state in which lasing is not inhibited such that a laser pulse is generated;
- and
- a pulse controller operable to provide a control signal to said electro-optic switch element to control repeated switching between said first loss state and said second loss state to trigger generation of a stream of laser pulses;
- wherein upon initiation of generation of laser pulses, said pulse controller generates control signals that progressively change said cavity light loss level of said second loss state towards a steady state second loss level such that laser pulse energy at startup is reduced compared to if said steady state second loss level was used immediately upon startup.
A method of operating a pulsed laser having a laser cavity, a laser gain medium within said laser cavity, an electro-optic switch element operable to change a light loss level of said laser cavity and laser gain medium between a first loss state in which lasing is inhibited and a second loss state in which lasing is not inhibited such that a laser pulse is generated, and a pulse controller operable to provide a control signal to said electro-optic switch element to control repeated switching between said first loss state and said second loss state to trigger generation of a stream of laser pulses;
- said method comprising the step of:
- upon initiation of generation of laser pulses, generating control signals that progressively change said cavity light loss level of said second loss state towards a steady state second loss level such that laser pulse energy at startup is reduced compared to if said steady state second loss level was used immediately upon startup.
Dependencies are inferred from the claim text.