Newport Corp., Irvine, CA, offers the fan-cooled 818P-500-55, water-cooled 818P-3KW-060, and high-sensitivity 818P-001-12NIR thermopile detectors. The 818P-500-55 can handle up to 500 W of continuous optical power, has a 55 mm dia. active area, and flat responses from 0.19–20 µm. Suited for use with lasers with a very high optical output power, the 818P-3KW-060 can handle up to 3 kW of CW optical power and up to 4 kW of power for up to 5 min. for cases when illumination is limited. The 818P-001-12NIR is designed to measure down to microwatt-level optical power with a 0.28–1.36 µm wavelength range and is insensitive to beam position.