Abstract:
PROBLEM TO BE SOLVED: To provide a laser device producing a Gaussian distribution point-shaped beam having a remarkably strong light intensity, by wavelength conversion using a nonlinear optical crystal.SOLUTION: A laser device includes a nonlinear optical crystal NL having a period polarization inversion structure on which laser light emitted from a photonic crystal surface emission laser element LD impinges. The different refractive index region 6B of a photonic crystal layer is arranged at the grating point position of a square grating. When the planar shape of each different refractive index region 6B is substantially rectangular equilateral triangle, two sides constituting the right angle extend along the longitudinal and lateral grid lines of a square grating, and the orientation parallel with or perpendicular to the hypotenuse of the triangle matches the orientation of polarization in the period polarization inversion structure of the nonlinear optical crystal NL.
Abstract:
A wavelength conversion element is provided as one including a monocrystalline nonlinear optical crystal. The nonlinear optical crystal has: a plurality of first regions having a polarity direction along a predetermined direction; a plurality of second regions having a polarity direction opposite to the predetermined direction; an entrance face into which a fundamental incident wave having a wavelength » and a frequency É is incident in a direction substantially perpendicular to the predetermined direction; and an exit face from which a second harmonic with a frequency 2É generated in the crystal emerges. The plurality of first and second regions are formed as alternately arranged in a period substantially equal to d expressed by a predetermined expression, between the entrance face and the exit face.
Abstract:
A wavelength conversion laser light source includes: an element temperature switching section that switches a temperature of the wavelength conversion element according to a harmonic wave output value as set in an output setting device, and the element temperature switching section for switching a temperature of a wavelength conversion element according to a harmonic wave output level as set in the output setting device, wherein the element temperature switch section includes an element temperature holding section that holds the wavelength conversion element at the temperature as switched by the element temperature switching section.
Abstract:
PROBLEM TO BE SOLVED: To provide a wavelength conversion element, a laser light source device, an image display device, and a method of manufacturing a wavelength conversion element, which are capable of controlling a polarization reversal structure formation step by using a magnesium-doped lithium tantalate single crystal having a congruent composition and is capable of stably manufacturing a wavelength conversion element having high conversion efficiency.SOLUTION: The method of manufacturing the wavelength conversion element includes a step of forming a periodic electrode 103 on a +z surface of an MgLN substrate 101 and forming a counter electrode 104 on a -z surface of the MgLN substrate 101, a heat treatment step of performing heat treatment after formation of the periodic electrode 103 and the counter electrode 104, and a field application step of applying a pulsed electric field between the period electrode 103 and the counter electrode 104 in a state of keeping the MgLN substrate 101 at 100°C or higher. A wavelength conversion element 100 has a polarization reversal structure formed by field application, on the MgLN substrate 101 after the heat treatment.