Source wavefront generation for a non-interferometric reconfigurable null test using a photonic lantern.

Area of Science:

• Optical Engineering
• Metrology
• Photonics

Background:

• Accurate testing of optical surfaces is crucial for high-performance optical systems.
• Existing null test methods can be complex and limited in adaptability, especially for freeform optics.

Purpose of the Study:

• To present a new method for generating reconfigurable custom wavefronts using a photonic lantern.
• To demonstrate the application of this method in non-interferometric null tests for various optical surface types.

Main Methods:

• Utilizing a photonic lantern, a fiber-optic device, to control output light fields.
• Modulating input intensity and phases at single-mode fiber ports to shape the wavefront.
• Employing a response-matrix inversion approach for wavefront generation and simulation.

Main Results:

• Successfully simulated the generation of a custom wavefront with a nineteen-port, non-mode-selective photonic lantern.
• Achieved a wavefront with a Root Mean Square (RMS) error of 71nm from the target in simulation.
• Simulated a compact, non-interferometric null test for freeform optical surfaces using the photonic lantern.

Conclusions:

• The photonic lantern offers a viable method for creating reconfigurable nulling wavefronts.
• This technique is applicable to testing spherical, aspheric, and particularly freeform optical surfaces.
• The proposed approach enables compact and adaptable optical metrology solutions.