Mode-locked laser autocollimator with an expanded measurement range

Area of Science:

• Optics and Photonics
• Metrology and Measurement Science

Background:

• Conventional laser autocollimators use single-wavelength lasers, limiting their tilt angle measurement range.
• Accurate angular displacement measurement is crucial in various scientific and industrial applications.

Purpose of the Study:

• To develop a laser autocollimator with an expanded range for tilt angle measurement.
• To investigate the feasibility of using a mode-locked laser as the light source.

Main Methods:

• A mode-locked femtosecond laser was utilized as the light source.
• A diffraction grating created spatially separated beams, focused into an array of light spots.
• A position-sensing photodiode detected linear displacement of the spot array.

Main Results:

• The prototype demonstrated a significantly expanded measurement range of 11000 arc-seconds.
• The use of a mode-locked laser enabled enhanced angular measurement capabilities.

Conclusions:

• Employing a mode-locked laser in autocollimators offers a viable method for extending tilt angle measurement range.
• The developed prototype validates the effectiveness of this advanced optical metrology technique.