Bessel beam

About: Bessel beam is a research topic. Over the lifetime, 1946 publications have been published within this topic receiving 42264 citations.

Demonstration of Bessel-like beam with variable parameters generated using cross-phase modulation.

Abstract: We propose a new method to generate Bessel-like beam using cross-phase modulation. The hot rubidium atomic sample is shown to have the ability to vary a Gaussian beam (probe beam) into a Bessel-like beam when the sample is illuminated with a counter-propagating Gaussian beam (pump beam) tuned close to the atomic resonances. It is demonstrated that the Bessel-like beam exhibits self-healing after encountering an obstruction on the beam path. The parameters of the Bessel-like beam are found to be easily adjusted by the pump beam power and sample temperature. Moreover, this method is even applicable to the probe beam of low power, having more practical value than the method using self-phase modulation which needs high input beam power. The merits of variable parameter, no requirement for input beam power, simple setup, and low cost would make this method of significance in a variety of applications, especially in those areas where Bessel beam power is needed to be low and parameter to be adjusted easily without changing the setup.

Generation of an elliptic Bessel beam

Abstract: In an elliptic coordinate system the solution for a diffraction-free beam is given by a Mathieu beam, which is mathematically complicated and therefore takes considerable computational time and a large memory space. A technique is reported for the generation of elliptic hollow beams, which are actually scaled versions of higher-order Bessel beams. The analysis is based on the fact that stretching coordinates in the space domain results in a contraction of the coordinates in the frequency domain, along with a change in the overall amplitude of the spectrum. The beam, produced holographically, is structurally stable and retains its shape up to approximately 1 m.

Bessel beams of finite amplitude in absorbing fluids

Abstract: Second-harmonic generation in a Bessel beam is investigated analytically, with emphasis on the effect of absorption. It is shown that absorption has a strong influence on the far-field beam profile. Numerical results are presented for higher harmonics and for waveform distortion in a Bessel beam that forms a shock.

Fabrication of photonic devices directly written in glass using ultrafast Bessel beams

Abstract: Optical waveguides have been inscribed in fused silica by focusing femtosecond laser pulses with an axicon The axicon is a conical lens that allows obtaining an optical beam with a transverse intensity profile that follows a zero-order Bessel function This profile is invariant along a certain distance (>1 cm) The advantage of using axicon is that the beam is focused along a narrow focal line of a few micron width Therefore the inscription of waveguides can be done without moving the glass sample The waveguides so fabricated exhibit low losses and no detectable birefringence due their excellent circular symmetry By translating the glass sample during the inscription process, we have induced a refractive index change along a thin plane in order to fabricate planar waveguides

Extended depth-of-field all-optical photoacoustic microscopy with a dual non-diffracting Bessel beam.

Abstract: All-optical photoacoustic microscopy (AOPAM) facilitates high-sensitivity, wide-bandwidth, volumetric imaging without coupling media. However, the rapid divergence of the Gaussian beam restricts the stability and depth-of-field in typical Gaussian AOPAM (G-AOPAM). Here we report an extended depth-of-field AOPAM using a dual non-diffracting Bessel beam (B-AOPAM). Benefiting from the designing, the B-AOPAM has the unique advantages of increasing depth resolving ability and improving photoacoustic detection sensitivity. The proposed scheme shows optimal lateral resolution of 2.4 μm and a long depth-of-focus of 635 μm, which is 10-fold larger than that of the G-AOPAM. The scattering phantoms and in vivo animal experiments demonstrated the imaging feasibility and capability of the B-AOPAM, which can provide noncontact, high spatial resolution imaging of non-flat tissue and contribute to future clinical applications.