Provided is a diode-pumped solid-state laser adapted for an intracavity sum-frequency mixing for generating a laser radiation of a visible wavelength range by performing a sum-frequency mixing of two laser inputs in a laser resonant cavity. The transparent plate is so mounted in the device and the device is so mounted on the gun, such that the critical image is seen by the user when and only when the axis of the gun barrel is parallel to the line of sight passing through the user’s eye and the center of the transparent plate. The first shaft member defines a first slot extending along and angled relative to a longitudinal axis. The method for making the composite pigment includes the step of introducing a soluble silicate compound into an aqueous medium containing a precipitate of calcium carbonate formed by carbonation of lime milk, and at a time when the calcium carbonate precipitation reaction has progressed to near completion. The output signal has a fundamental frequency and a gating frequency.