Demonstration of a Fresnel axicon.
We design and manufacture a Fresnel axicon (fraxicon) that generates a quasi-diffraction-free/Bessel beam with a large depth of field. The novel optical element is characterized with both coherent and incoherent light, and its behavior is compared with that of a classical axicon. While the fraxicon exhibits a strong interference pattern in the on-axis intensity distribution, it can be smoothed out when using broadband light, partial spatial coherence light, or by period randomization. As inexpensive, compact/lightweight, and low-absorption elements, fraxicons may find applications in imaging, illumination, and situations where low absorption and dispersion are important.
School of Advanced Technology, Algonquin College, Ottawa, Ontario K2G 1V8, Canada.
Kevin
K
Gourley
Ilya
I
Golub
Brahim
B
Chebbi