Abstract

We describe two novel devices for optical beam alignment. One uses an elliptical mirror and a turning mirror to allow for a variable angle with a fixed position of incidence upon a sample. The other uses a parabolic mirror and a turning mirror to allow for a variable position with a fixed angle of incidence upon a sample. These devices have no chromatic dispersion, and the time of flight through either of these devices is a constant independent of the angle and position of incidence. Therefore, these devices are particularly useful for experiments and applications involving ultrashort pulses because the alignment of the beam on a sample under test can be adjusted continuously while preserving precise timing a requirement that might be imposed, for example, by a second pump beam of ultrashort pulses. Cascaded together, these devices allow placement of a laser beam upon a sample with arbitrary angle and position of incidence. Other combinations facilitate the capture of a signal beam by a detector in a measurement taken as a continuous function of the alignment parameters.

© 1990 Optical Society of America