The characteristic properties of noncritically phase‐matched frequency doubling in KTiOPO4have been investigated using ∼1 &mgr;m radiation from a Styryl‐13 dye laser. Noncritically phase‐matched type II second‐harmonic generation was found to occur at 994.3 nm. The unusually wide angle, temperature, and wavelength tolerances observed for this nonlinear process are attractive for the design of practical blue‐green laser sources. A special strained‐layer InGaAs diode laser was fabricated to operate at 994 nm and generation of blue‐green 497 nm radiation by noncritically phase‐matched frequency doubling was demonstrated.