US 7,254,156 B2Granted

Line-narrowed dye laser

AssigneeCoherent, Inc.

InventorsBernd Nikolaus, Ralph Delmdahl, Eckard Zanger, Christoph Eisenhardt

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Abstract

A dye-laser includes a resonator formed between two mirrors. The resonator has a longitudinal Z-axis and transverse X- and Y-axes perpendicular to each other and perpendicular to the Z-axis. A beam of laser radiation circulates in the laser resonator generally in a path along the Z-axis. An optical arrangement is provided for expanding the circulating beam in the Y-axis in one circulation direction and correspondingly compressing the expanded beam in the opposite circulation direction. A diffraction grating having rulings parallel to an X-Z plane of the resonator is located in the resonator in the path of the Y-axis expanded beam. The resonator and the diffraction grating are configured and arranged such that the Y-axis expanded beam is incident on the diffraction grating at a compound angle, is diffracted by the diffraction grating onto one of the resonator mirrors, and is reflected by that mirror back onto the grating such that the circulating laser radiation is incident on the diffraction grating twice per round trip in the resonator.

Claims16

Dependent claims

A laser, comprising:

a laser resonator including a gain-medium, said laser resonator being formed between first and second mirrors and having a longitudinal Z-axis and transverse X- and Y-axes perpendicular to each other and perpendicular to said Z-axis;
an arrangement for energizing said gain-medium, thereby causing a beam of laser radiation to circulate in said laser resonator generally in a path along said Z-axis thereof;
an optical arrangement for expanding said circulating beam in one circulation direction thereof in said Y-axis of said resonator and correspondingly compressing said expanded beam in an opposite circulation direction of said beam;
and
a diffraction grating having rulings parallel to a X-Z plane of said resonator and located in said laser resonator in the path of said Y-axis expanded beam, said resonator and said diffraction grating therein being configured and arranged such that said Y-axis expanded beam is incident on said diffraction grating at a compound angle thereto, is diffracted by said diffraction grating onto said first mirror, and is reflected by said first mirror back onto said grating such that laser radiation circulating in said laser resonator is incident on said grating twice per round trip in said resonator and wherein said laser resonator includes a wedge-shaped optical element located in said laser resonator in the path of said expanded beam between said beam expanding arrangement and said diffraction grating, said wedge-shaped optical element having a wedge angle in said X-Z plane of said resonator and being arranged with respect to said diffraction grating and said first mirror, such that said expanded beam is transmitted therethrough, and is incident on said diffraction grating at said compound angle.

2 more elements

A laser, comprising:

a first laser resonator including a gain-medium, said laser resonator being formed between first and second mirrors and having a longitudinal Z-axis and transverse X- and Y-axes perpendicular to each other and perpendicular to said Z-axis;
an arrangement for energizing said gain-medium thereby causing a beam of laser radiation to circulate in said first laser resonator generally in a path along said Z-axis thereof;
an optical arrangement for expanding said circulating beam in one circulation direction thereof in said Y-axis of said first laser resonator and correspondingly compressing said expanded beam in an opposite circulation direction of said beam;
a diffraction grating located in said first laser resonator in the path of said Y-axis expanded beam, said diffraction grating having rulings parallel to an X-Z plane of said resonator;
and
a wedge-shaped optical element located in said first laser resonator between said beam expanding arrangement and said diffraction grating, said wedge-shaped optical element having a wedge angle in said X-Z plane of said first laser resonator and being arranged with respect to said diffraction grating and said first mirror, such that at least a part of said expanded beam is transmitted therethrough, is incident on said diffraction grating at a compound angle, is diffracted by said diffraction grating onto said first mirror, and is reflected by said first mirror back onto said grating in a reverse direction along said incident path, whereby laser radiation circulating in said first laser resonator is incident twice per round trip therein.

3 more elements

A laser, comprising:

a laser resonator having first and second branches and a common path said laser resonator and said branches thereof having a longitudinal Z-axis and transverse X- and Y-axes perpendicular to each other and perpendicular to said Z-axis;
a gain-medium located in said laser resonator on said common path thereof;
an arrangement for energizing said gain-medium thereby causing a beam of laser radiation to circulate along said common path of said laser resonator generally in a path along said Z-axis thereof;
said first branch of said laser resonator being formed between first and second mirrors;
an optical arrangement for expanding said common-path circulating beam in one circulation direction thereof in said Y-axis of said first laser resonator and correspondingly compressing said expanded beam in an opposite circulation direction of said expanded beam;
a diffraction grating located in said laser resonator in the path of said Y-axis expanded beam, said diffraction grating having rulings parallel to an X-Z plane of said resonator;
and
a wedge-shaped optical element located in said first laser resonator between said beam expanding arrangement and said diffraction grating, said wedge-shaped optical element having a wedge angle in said X-Z plane of said laser resonator and being configured and arranged with respect to said Z axis, said diffraction grating and said first mirror, such that at a first portion of said expanded beam is transmitted therethrough, is incident on said diffraction grating at a compound angle thereto, is diffracted by said diffraction grating onto said first mirror of said first branch of said laser resonator, and is reflected by said first mirror back onto said grating in a reverse direction along said incident path, whereby laser radiation circulating in said first branch of said laser resonator is incident twice per round trip therein;
said second branch of said laser resonator being formed between said second mirror and said diffraction grating, said wedge-shaped optical element and said diffraction grating being arranged such that a second portion of said Y-axis expanded beam bypasses said wedge-shaped element, is incident on said diffraction grating aligned at a simple angle thereto, and is diffracted back along said incident path;
and
wherein, radiation circulating in said first branches and second branches of said laser resonator has respectively first and second wavelengths within the gain-bandwidth of the gain-medium, said first and second wavelengths being different, and wherein said laser resonator is arranged to deliver both of said radiation wavelengths as output radiation.

8 more elements

A method of operating a laser resonator, the laser resonator including a gain-medium, first and second mirrors, a diffraction grating located between the first and second mirrors and a beam expander for expanding a beam circulating in one direction in the resonator onto the diffraction grating and compressing the expanded beam onto a common path in the opposite direction of circulation, the method comprising:

dividing the expanded beam into first and second portions such that said first portion of said beam circulates between said first and second mirrors and is incident twice per round trip on said diffraction grating, and such that said second portion of said beam circulates between said diffraction grating and said first mirror and is thereby incident only once per round trip on said diffraction grating said beam dividing being such that said first and second beam portions are incident at respectively first and second different angles on said diffraction grating;
and
selecting and arranging the gain-medium in the common path in the resonator such that both portions of the beam are amplified thereby, whereby the resonator generates laser radiation at first and second different wavelengths corresponding to the first and second different incidence angles on the grating.

Dependencies are inferred from the claim text.

Facts

Application: 11/038,335Filed 19 Jan 2005
Published: US 2006/0159150 A120 Jul 2006
Granted: 7 Aug 2007
Term ends: Not estimatedThe source records don’t support an estimate.

Classification8 codes

H01S 3/1055
By controlling the mutual position or the reflecting properties of the reflectors of the cavity , e.g. by controlling the cavity length: one of…
H01S 3/005
Lasers, i.e. devices using stimulated emission of electromagnetic radiation in the infrared, visible or ultraviolet wave range: optical devices…
H01S 3/08059
Construction or shape of optical resonators or components thereof: constructional details of the reflector, e.g. shape
H01S 3/0809
Multiple-wavelength emission: two-wavelenghth emission