High damage threshold frequency conversion system

An apparatus for laser frequency conversion having a high damage threshold, comprising:

• a fundamental laser light source configured to generate fundamental wavelength laser light;
• at least one nonlinear optical crystal configured to generate alternate wavelength light by frequency converting at least a portion of received laser light to alternate wavelength light;
• a dual wavelength Brewster angle waveplate configured to receive fundamental wavelength light and alternate wavelength light emanating from the at least one nonlinear optical crystal, the dual wavelength Brewster angle waveplate further configured to rotate a polarization of the fundamental wavelength light relative to the alternate wavelength light such that the fundamental wavelength light and the alternate wavelength light have substantially the same polarization;
• a set of Brewster angle wavefront processing optics configured to receive fundamental wavelength light and alternate wavelength light from the dual wavelength Brewster angle waveplate, the set of Brewster angle wavefront processing optics further configured to condition the fundamental wavelength light and the alternate wavelength light emanating from the dual wavelength Brewster angle waveplate;
• a harmonic separator configured to receive fundamental wavelength light and alternate wavelength light from the set of Brewster angle wavefront processing optics, the harmonic separator configured to at least partially separate the fundamental wavelength light from the alternate wavelength light;
• and
• at least one Brewster angle output window configured to transmit at least one of the fundamental wavelength light or the alternate wavelength light from an interior portion of a laser frequency conversion system to a region external to the laser frequency conversion system.

A method for laser frequency conversion with high damage threshold, comprising:

• providing a fundamental laser light source;
• generating fundamental wavelength laser light utilizing the fundamental laser light source;
• generating first alternate wavelength light by frequency converting at least a portion of the fundamental laser light to first alternate wavelength light utilizing a first nonlinear optical crystal;
• generating second alternate wavelength light by frequency converting at least a portion of the first alternate wavelength light to second alternate wavelength light utilizing a second nonlinear optical crystal;
• rotating a polarization of the first alternate wavelength light relative to the second alternate wavelength light such that polarization of the first alternate wavelength light and polarization of the second alternate wavelength light are substantially the same utilizing a dual wavelength Brewster angle waveplate;
• conditioning the first alternate wavelength light and second alternate wavelength light utilizing Brewster angle wavefront processing optics;
• separating at least a portion of the first alternate wavelength light from the second alternate wavelength light utilizing a harmonic separator including a harmonic separation element having a first Brewster angle surface, a total internal reflection surface, and a second Brewster angle surface;
• and
• transmitting at least one of the first alternate wavelength light or the second alternate wavelength light from an interior portion of a laser frequency conversion system to a region external to the laser frequency conversion system.