| 摘要 |
A device (400, NLC) for second harmonic generation comprises: - a wavelength-converting portion (MCP) for converting energy of first light (B1) into second light (B2) at a conversion efficiency, the second light (B2) having a shorter wavelength than the first light (B1), the conversion efficiency having a maximum at a temperature-dependent spectral location (lambdaCE), - a diffractive grating (G1) for reflecting a spectrally selected portion of the first light (B1), said portion being determined by a reflection band of the grating (G1), and - a strain-inducing element (SE1, SE2, SE3, SE4), wherein the optical device (400, NLC) is arranged to operate such that: - the temperature of the wavelength-converting portion (MCP) and the temperature of the grating (G1) depend on an operating temperature of the device (400, NLC), - a change (∆T) in the operating temperature causes a first spectral shift (∆lambdaCE) in the spectral position (lambdaCE) of the maximum conversion efficiency and a second spectral shift in (∆lambdaPB) the spectral position (lambdaPB) of the reflection band, and - the strain-inducing element (SE1, SE2, SE3, SE4) is arranged to induce temperature-dependent strain in the wavelength-converting portion (MCP) and/or in the diffractive grating (G1) so as to reduce a difference between the first spectral shift (∆lambdaCE) and the second spectral shift (∆lambdaPB). |
