Detection of Bessel beams with digital axicons

Abstract

We propose a simple method for the detection of Bessel beams with arbitrary radial and azimuthal indices, and then demonstrate it in an all-digital setup with a spatial light modulator. We confirm that the fidelity of the detection method is very high, with modal cross-talk below 5%, even for high orbital angular momentum carrying fields with long propagation ranges. To illustrate the versatility of the approach we use it to observe the modal spectrum changes during the self-reconstruction process of Bessel beams after encountering an obstruction, as well as to characterize modal distortions of Bessel beams propagating through atmospheric turbulence.

Structured Light in Turbulence

“…The idea has been around since the 1980s in fibre and gained momentum in the past 10 years after seminal MDM demonstrations [10][11][12], inspired by work of the Nakazawa group. In free-space the development followed advances in orbital angular momentum (OAM), one of which was a proof-of-principle demonstration of communication down a corridor in the University of Glasgow [13], with many seminal demonstrations quickly following [14][15][16] including interesting applications such as communications to aerial platforms [17], and later with other mode sets [18][19][20][21][22][23][24], as well as with quantum states in the spatial mode basis [25][26][27][28][29][30][31][32][33][34].…”

Mode-Division-Multiplexing of Multiple Bessel-Gaussian Beams Carrying Orbital-Angular-Momentum for Obstruction-Tolerant Free-Space Optical and Millimetre-Wave Communication Links

“…First, the term removes the helical phases associated with OAM beams. The second term in the above transmission function represents a reversed axicon and is needed to remove the conical phases associated with the BG beams, such that the desired BG beam is converted back into a fundamental Gaussian beam for coupling into a single mode fibre (SMF) 31 . The received signal is then fed to a coherent receiver for detection and bit-error rate (BER) measurements.…”

Tailoring light with a digital micromirror device

“…DMDs with the ability to shape the Laguerre–Gaussian or Bessel beams will potentially provide a means to encode quantum information with a considerably fast speed. Contrarily, DMDs encoded with the holograms for beams with opposite topological charge can be applied for the reading of quantum information, such as Bessel beam detection with digital axicon. It is pointed out that such a technique reads the quantum information through complex field demodulation, and thus the low efficiency brought by the amplitude modulation device has no significant impact on the measurement.…”