Precise multipass Herriott cell design: derivation of controlling design equations

Area of Science:

• Optics and Photonics
• Optical Engineering
• Laser Technology

Background:

• Multipass Herriott cells are optical systems that use mirrors to fold a light beam path.
• Current designs often rely on the thin lens approximation, leading to inaccuracies.
• Spherical aberration and finite optic width in traditional designs cause imperfect beam patterns.

Purpose of the Study:

• To derive exact design equations for Multipass Herriott cells.
• To address limitations of the thin lens approximation in Herriott cell design.
• To enable simultaneous, precise reentrant conditions for multiple concentric beam patterns.

Main Methods:

• Derivation of exact design equations for Herriott cells.
• Analysis of beam patterns with spherical and elliptical mirrors.
• Investigation of reentrant conditions for multiple concentric beams.

Main Results:

• Exact design equations for Herriott cells were derived, improving accuracy.
• It was demonstrated that spherical mirrors cannot achieve simultaneous reentrant conditions for multiple concentric beams.
• A design solution using elliptical mirrors was developed, allowing simultaneous reentrant conditions for numerous beams.

Conclusions:

• The thin lens approximation in Herriott cell design leads to significant inaccuracies.
• Elliptical mirrors offer a viable solution for achieving precise, simultaneous multi-beam patterns in Herriott cells.
• Exact design equations and the use of elliptical mirrors enhance the performance and applicability of Multipass Herriott cells.