Abstract

A high-contrast imaging technique for phase objects based on the optical vortex coronagraph (OVC) is proposed. This method offers the unique advantage of background-free imaging due to the introduction of azimuthal phase in the Fourier plane. We employed the OVC method to detect femtosecond laser-induced air plasma and compared it with the classic diffractometry and fluorescent imaging methods. We achieved a phase sensitivity of ∼0.035 waves that surpassed the capabilities of the other two methods. The combination of this highly sensitive imaging technique with the pump–probe method holds promise for applications in ultrafast imaging of laser–material interactions.

© 2023 Optica Publishing Group

Nonlinear optical vortex coronagraph

Einstom Engay and Peter John Rodrigo
Opt. Lett. 45(6) 1579-1582 (2020)

High-charge and multiple-star vortex coronagraphy from stacked vector vortex phase masks

Artur Aleksanyan and Etienne Brasselet
Opt. Lett. 43(3) 383-386 (2018)

Femtosecond filamentation of optical vortices for the generation of optical air waveguides

Silin Fu, Benoit Mahieu, André Mysyrowicz, and Aurelien Houard
Opt. Lett. 47(19) 5228-5231 (2022)

Self-eclipsing: alignment-free vortex coronagraphy

Artur Aleksanyan and Etienne Brasselet
Opt. Lett. 42(7) 1237-1240 (2017)

Sub-Rayleigh optical vortex coronagraphy

E. Mari, F. Tamburini, G. A. Swartzlander, A. Bianchini, C. Barbieri, F. Romanato, and B. Thidé
Opt. Express 20(3) 2445-2451 (2012)