External-cavity optically-pumped semiconductor lasers (OPS-lasers) including an OPS-structure having a mirror-structure surmounted by a surface-emitting, semiconductor multilayer (periodic) gain-structure are disclosed. The gain-structure is pumped by light from diode-lasers. The OPS-lasers can provide fundamental laser output-power of about two Watts (2.0 W) or greater. Intracavity frequency-converted arrangements of the OPS-lasers can provide harmonic laser output-power of about one-hundred milliwatts (100 mW) or greater, even at wavelengths in the ultraviolet region of the electromagnetic spectrum. These high output powers can be provided even in single axial-mode operation. Particular features of the OPS-lasers include a heat sink-assembly for cooling the OPS-structure, a folded resonator concept for providing optimum beam size at optically-nonlinear crystals used for frequency conversion, preferred selection of optically-nonlinear materials for frequency-conversion, and compound resonator designs for amplifying second harmonic-radiation for subsequent conversion to third or fourth harmonic radiation.
PRIORITY INFORMATION
This application is a continuation of application Ser. No. 10/180,825, filed Jun. 26, 2002 now U.S. Pat. No. 6,683,901, which is in turn a continuation of application Ser. No. 09/938,226, filed Aug. 23, 2001, now U.S. Pat. No. 6,438,153, which is in turn a continuation of application Ser. No. 09/263,325, filed Mar. 5, 1999, now U.S. Pat. No. 6,285,702.
Control of average wavelength-converted power and/or wavelength converted pulse energy is described. One or more seed pulses may be generated and amplified with an optical amplifier to produce one or more amplified pulses. The amplified pulses may be wavelength converted to produce one or more wavelength converted pulses characterized by an average wavelength-converted power or pulse energy. Wavelength-converted power or pulse energy may be controlled by adjusting wavelength conversion efficiency without substantially changing the amplified power or pulse energy. Average wavelength-converted power may be controlled over a time scale comparable to a pulse period of the amplified pulses without adjusting an average power of the amplified pulses over the time scale comparable to a pulse period of the amplified pulses. A wavelength-converted optical system, may comprise a seed source, an optical amplifier optically coupled to the seed source, a wavelength converter optically coupled to the optical amplifier; and a controller operably coupled to the seed source and/or optical amplifier and/or wavelength converter. The controller may include logic adapted to control an average wavelength-converted power of an output of the wavelength converter over a time scale comparable to a pulse period of amplified pulses from the optical amplifier without adjusting an average power of the amplified pulses over that time scale. Alternatively, the controller logic may be adapted to control wavelength-converted pulse energy by adjusting the wavelength conversion efficiency without substantially changing the pulse energy of the amplified pulses.
