An optical navigation device includes a housing, a light source, a
navigation sensor, and optics. In accordance with the invention, the
light source is a vertical cavity surface emitting laser (VCSEL) that is
configured to generate coherent light in the visible light spectrum. For
example, the VCSEL generates red coherent light in the range of 600-700
nm. In an embodiment, the VCSEL generates red coherent light at 665
nm.+-.20 nm. Because the light generated by the VCSEL is in the visible
light spectrum, a human will sense contact with the corresponding beam
and will naturally react to avoid injury. This enhances the overall
safety of an optical mouse. Additionally, when using a VCSEL that
generates visible red light, it is easy to visually determine whether or
not the beam is focused directly on a measurement sensor during
calibration.