Optical array comprising a beam splitter

Patent metadata

Field	Value
Publication number	US-9941653-B2
Application number	US-201515116175-A
Country	US
Kind code	B2
Filing date	Feb 3, 2015
Priority date	Feb 3, 2014
Publication date	Apr 10, 2018
Grant date	Apr 10, 2018

Abstract

The invention relates to an optical array comprising a splitting element ( 1 ) which splits an input beam (E) into at least two partial beams (T 1 , T 2 , T 3 , T 4 ), at least one optical element (V 1 , V 2 , V 3 , V 4 , MV) through which at least one of the partial beams (T 1 , T 2 , T 3 , T 4 ) propagates, and at least one combining element ( 4 ) which spatially superimposes the partial beams (T 1 , T 2 , T 3 , T 4 ) in one output beam (A). The object of the invention is to provide an optical array which is improved over the prior art and which permits effective and simple splitting of the input light beam, in particular a laser beam with pulsed or continuous emission. The invention achieves this object in that the splitting element ( 1 ) and/or the combining element ( 4 ) each have a partially reflective element ( 2, 2 ′) which reflects the radiation of the input beam (E) or of the output beam (A) two or more times, wherein the partially reflective element ( 2, 2 ′) has zones (a, b, c, d) of different reflectivity.

First claim

The invention claimed is:

1. An optical array, comprising:
a splitting element which splits an input beam into at least two partial beams,
an optical element through which at least one of the partial beams propagates, and
a combining element which spatially superposes the partial beams in one output beam, wherein the combining element is arranged antisymmetrically with respect to the splitting element in such a way that path length differences of the at least two partial beams cancel out,
further wherein of the splitting element has a first partially reflective element and the combining element has a second partially reflective element,
wherein the first partially reflective element and the second partially reflective element reflect the radiation of the input beam and the output beam at least two times,
further wherein the first and second partially reflective elements have zones of different reflectivity,
and the optical element is one of an optical amplifier or a nonlinear optical element for spectral broadening.

2. The optical array as claimed in claim 1 , wherein the reflectivity of the zones of the first and second partially reflective elements is along a direction located in the reflection plane of the radiation decreases or increases.

3. The optical array as claimed in claim 1 , wherein the splitting element comprises a first reflective element and the combining element comprises a second reflective element, wherein the radiation is reflected between the first and second partially reflective elements and the first and second reflective elements.

4. The optical array as claimed in claim 3 , wherein the surfaces of the first and second reflective elements is are plane-parallel to the surfaces of the first and second partially reflective elements.

5. The optical array as claimed in claim 1 , wherein the radiation strikes the first and second partially reflective elements at an angle which deviates from 90°.

6. The optical array as claimed in claim 1 , wherein the partial beams propagate in a common plane, parallel and with equal distance.

7. The optical array as claimed in claim 1 , wherein the partial beams propagate in a spatially separated manner through the optical element.

8. The optical array as claimed in claim 7 , wherein the optical element is a multicore fiber having a plurality of spatially separate waveguide structures, wherein each waveguide structure guides one of the partial beams.

9. The optical array as claimed in claim 1 , further comprising at least two spatially separate optical elements corresponding to the at least two partial beams, wherein the partial beams propagate through the corresponding optical elements.

10. The optical array as claimed in claim 9 , wherein the optical elements are optical fibers, wherein each optical fiber guides one of the partial beams.

11. The optical array as claimed in claim 1 , further comprising a phase matching element which is arranged in a beam direction, said beam direction one of upstream or downstream of the optical element, wherein said beam direction influences the phase of the radiation of at least one of the partial beams.

12. The optical array as claimed in claim 11 , further comprising a control loop, in which the phase of the radiation of the partial beams is a set variable.

13. A system, comprising:
a laser radiation source, which emits an input beam, and
an optical array, comprising:
a splitting element which splits an input beam into at least two partial beams,

an optical element through which at least one of the partial beams propagates, and
a combining element which spatially superposes the partial beams in one output beam, wherein the combining element is arranged antisymmetrically with respect to the splitting element in such a way that path length differences of the at least two partial beams cancel out,
further wherein at least one of the splitting element has a first partially reflective element and the combining element has a second partially reflective element,
wherein the first partially reflective element and the second partially reflective element reflect the radiation of the input beam and the output beam at least two times,
further wherein the first and second partially reflective elements have zones of different reflectivity,
and the optical element is one of an optical amplifier or a nonlinear optical element for spectral broadening.

14. The system as claimed in claim 13 , wherein the laser radiation source is a continuous wave laser, wherein the power of the laser radiation of the continuous wave laser in each partial beam is amplified by way of optical amplification to at least 100 W.

15. The system as claimed in claim 14 , wherein the power of the laser radiation of the continuous wave laser in each partial beam is amplified by way of optical amplification to at least 500 W.

16. The system as claimed in claim 14 , wherein the power of the laser radiation of the continuous wave laser in each partial beam is amplified by way of optical amplification to at least 1 kW.

17. The system as claimed in claim 13 , wherein the laser radiation source is a short pulse laser, wherein the pulse energy of the short pulse laser pulses at the output of the optical element in each partial beam is at least 0.1 mJ.

18. The system as claimed in claim 17 , wherein the pulse energy of the short pulse laser pulses at the output of the one optical element in each partial beam is at least 0.5 MJ.

19. The system as claimed in claim 17 , wherein the pulse energy of the short pulse laser pulses at the output of the optical element in each partial beam is at least 1 mJ.

Assignees

• Fraunhofer Ges Forschung
• Univ Jena Friedrich Schiller
• Fraunhofer Ges Forschung
• Univ Jena Friedrich Schiller

Inventors

• Klenke Arno
• Limpert Jens
• Otto Hans-Jurgen
• Tunnermann Andreas

Classifications

• G02B27/1006

  for splitting or combining different wavelengths (G02B27/1086, G02B27/141 take precedence) · CPC title

• H01S3/0078 Primary

  Frequency filtering · CPC title

• G02B27/145

  having sequential partially reflecting surfaces · CPC title

• H01S3/0092

  Nonlinear frequency conversion, e.g. second harmonic generation [SHG] or sum- or difference-frequency generation outside the laser cavity (nonlinear frequency conversion per se G02F1/35) · CPC title

• H01S3/2308

  Amplifier arrangements, e.g. MOPA · CPC title