Control of relaxation oscillations in intracavity optical parametric oscillators

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EP 2 662 940 A3

(12)	EUROPEAN PATENT APPLICATION

(88)	Date of publication A3:
	08.01.2014 Bulletin 2014/02

(43)	Date of publication A2:
	13.11.2013 Bulletin 2013/46

(21)	Application number: 13177766.6

(22)	Date of filing: 30.07.2009

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Int. Cl.:

H01S 3/109 ^(2006.01)
H01S 3/13 ^(2006.01)
H01S 3/082 ^(2006.01)
H01S 3/107 ^(2006.01)
H01S 3/16 ^(2006.01)
H01S 3/06 ^(2006.01)

H01S 3/108 ^(2006.01)
H01S 3/136 ^(2006.01)
H01S 3/081 ^(2006.01)
H01S 3/0941 ^(2006.01)
H01S 3/08 ^(2006.01)

(84)	Designated Contracting States:
	AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HR HU IE IS IT LI LT LU LV MC MK MT NL NO PL PT RO SE SI SK SM TR

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Priority:

31.07.2008 GB 0813980

(62)	Application number of the earlier application in accordance with Art. 76 EPC:
	09784820.4 / 2308141

(71)	Applicant: University Court of The University of St Andrews
	St Andrews Fife KY16 9AJ (GB)

(72)	Inventors:
	Dunn, Malcolm Harry St Andrews Fife KY16 9SS (GB) Stothard, David James Mark St Andrews Fife KY16 9SS (GB) Rae, Cameron Francis St Andrews Fife KY16 9SS (GB)

(74)	Representative: Kinsler, Maureen Catherine et al
	Marks & Clerk LLP Atholl Exchange 6 Canning Street Edinburgh EH3 8EG Edinburgh EH3 8EG (GB)

(54)	Control of relaxation oscillations in intracavity optical parametric oscillators

(57) An intra-cavity optical parametric oscillator including means for providing a non-linear loss for suppressing relaxation oscillations, wherein the means for providing the non-linear loss are variable. The laser resonator may be delimited by the back-facet HR coating (16) of an end-pumped laser gain medium (14) and an output coupler (18). The laser comprises an intra-cavity optical parametric oscillator with a non-linear crystal (24), the singly resonant OPO which is signal-resonant comprises a mirror (26) and the common output coupler (18) and a dichroic beam splitter (22) reflecting the signal radiation and transmitting the laser fundamental. The amplitude of circulating laser fundamental may be stabilized inside the laser resonator by a feedback loop comprising a photodetector (38), a controller (40) and an optical modulator (3) in the resonator.