Power Technology Inc.'s 4-mW blue IQ laser diode module is a lower-noise alternative to 473-nm Nd:YAG lasers. The instrument-quality device operates at 473 ±5 nm and has a precision current source and a PID temperature control loop. It is suitable for fluorescence, spectroscopy, high-resolution printing, interferometry, microscopy and other applications that require a stable wavelength and output. Features include an adjustable focus and quality glass optics. Available with standard elliptical output or with a circularized beam and with continuous-wave or modulated output, the laser diode can operate in constant current or automatic power control mode. Beam-expanding optics are optional.