Control of spatial mode distribution of a large-core laser diode system
OwnerMieng Paiinventor
Life of this patent
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Abstract
System and method for operating a single unit of light-amplifying medium, structured to produce light with a complex spatial spectrum including multitude of high-order spatial modes, in external cavity configured, in conjunction with an optical etalon installed intra-cavity, to reduce spatial spectrum of such light to provide an output containing smaller number of high-order spatial modes and, optionally, only the lowest spatial mode at power levels on the order of 1 W or higher (for example, tens or hundreds of Watts).
Claims20
A method for controlling a transverse distribution of light generated by a light-amplifying medium (LAM) at an operational wavelength, the method comprising:
- operating said LAM within an external cavity (EC), which is configured as a loop cavity, such as to produce a first light output at said operational wavelength,
- said loop cavity being defined by at least three mirrors at least one of which is dimensioned to ensure that a first angle is smaller than a second angle,
- and
- impinging said generated light onto an optical etalon filter disposed intracavity across a cavity axis between first and second mirrors of the at least three mirrors,
- wherein the first angle is defined as an angle formed between
- a cavity line, that connects
- (i) a first point defined on a perimeter of a clear aperture of a first chosen mirror of said at least three mirrors with
- (ii) a second point on a perimeter of a clear aperture of a second chosen mirror of said at least three mirrors,
- and
- a portion of an optical axis of said EC that connects said first and second chosen mirrors,
- and
- wherein the second angle is determined based on a non-zero angle at which said generated light, that is incident on said optical etalon filter from the first mirror, constructively interferes with itself upon interaction with the optical etalon such as to propagate towards the second mirror.
A laser system configured to generate first light at an operational wavelength, the laser system comprising:
- a loop optical cavity formed by at least three mirrors, said cavity having an optical axis;
- a light amplifying medium (LAM) disposed coaxially with said optical axis inside said loop optical cavity such that said loop optical cavity forms an external cavity (EC) with respect to said LAM;
- and
- an optical etalon filter disposed intra-EC across the optical axis,
- wherein one or more mirrors of said at least three mirrors is dimensioned to ensure that a first angle is smaller than a second angle,
- wherein the first angle being defined as an angle formed between
- a cavity line, that connects
- (i) a first point defined on a perimeter of a clear aperture of a first mirror of said at least three mirrors with
- (ii) a second point on a perimeter of a clear aperture of a second mirror of said at least three mirrors,
- and
- a portion of the optical axis that connects said first and second mirror,
- and
- wherein the second angle is determined based on a non-zero angle at which light, that is incident on said optical etalon filter intracavity from the first mirror, constructively interferes with itself upon interaction with the optical etalon such as to propagate towards the second mirror.
A laser system comprising:
- a large-core laser diode (LD) chip disposed in an external cavity (EC) defined by at least three mirrors;
- an optical etalon and an optical isolator positioned in said EC;
- a seed laser configured outside of said EC such as to transmit light that has been generated at an operational wavelength by the seed laser through a seed mirror of said at least three mirrors and through said LD chip;
- wherein said LD chip is configured to generate N transverse modes at said operational wavelength when operated without EC;
- wherein said EC forms a closed loop;
- and
- wherein said EC is configured such that
- light at the operational wavelength that is incident from a first mirror onto said optical etalon at a largest angle, at which such is supported to circulate in the EC, does not propagate towards a second mirror of the EC upon interaction with said optical etalon;
- and,
- when operating at said operational wavelength, said laser system generates light forming a light output that contains M transverse modes, M<N.
Dependencies are inferred from the claim text.