World Star Technologies Inc. has developed CW, 660-nm, 100-mW red laser diode modules that are designed to enable OEMs to upgrade their systems. They exhibit <1% stability, <0.5-mrad beam divergence and <0.5% noise rms. The boresight is accurate to <2.5 mm/m, and the wavelength drifts 0.2 nm/°C. Temperature control is optional. The module, which is compatible with TTL modulation and line-generating optics, can be used for particle counting, fluorescence excitation or flow cytometry.