Abstract
We report on a novel kind of accelerating beams that follow parabolic paths in free space. In fact, this accelerating peculiar polygon beam (APPB) is induced by the spectral phase symmetrization of the regular polygon beam (RPB) with five intensity peaks, and it preserves a peculiar symmetric structure during propagation. Specially, such beam not only exhibits autofocusing property, but also possesses two types of accelerating intensity maxima, i.e., the cusp and spot-like structure, which does not exist in the previously reported accelerating beams with a single kind of lobes. We also provide a detailed insight into the theoretical origin and characteristics of this spatially accelerating beam through catastrophe theory. Moreover, an experimental scheme based on a digital micromirror device (DMD) with the binary spectral hologram is proposed to generate the target beam by precise modulation, and a longitudinal needle-like focus is observed around the focal region. The experimental results confirm the peculiar features presented in the theoretical findings. Further, the APPB is verified to exhibit self-healing property during propagation with either obstructed cusp or spot reconstructing after a certain distance. Hence, we believe that the APPB will facilitate the applications in the areas of particle manipulation, material processing and optofludics.
Highlights
We report on a novel kind of accelerating beams that follow parabolic paths in free space
The Airy beams are examples of a canonical catastrophe, i.e., the hyperbolic umblics (HUs), whereas the regular polygon beam (RPB) belong to the elliptic umblics (EUs)[24]
The phase function for accelerating polygon beam with five cusp points in the spectral space is expressed as: φ(ε, η) = ε5 + η5 + 5(ε4η + εη4) − 10(ε3η2 + ε2η3). This kind of accelerating quinary-cusp beam was theoretically predicted in 2010 24. Such beam has been experimentally demonstrated by projecting the predesigned spectral phase mask onto the liquid-crystal spatial light modulator (LC-SLM), and the beam profiles can be observed at the focal plane of a Fourier transforming lens[31]
Summary
We report on a novel kind of accelerating beams that follow parabolic paths in free space This accelerating peculiar polygon beam (APPB) is induced by the spectral phase symmetrization of the regular polygon beam (RPB) with five intensity peaks, and it preserves a peculiar symmetric structure during propagation. The created APPB is verified to exhibit self-healing property during propagation with either obstructed cusp or spot point reconstructing after a certain distance Such unique kind of structured beam with two types of intensity maxima can offer great potentials in the practical applications. We anticipate this novel kind of accelerating polygon beam will benefit the applications in the areas of particle manipulation, precise material processing and optofluidics
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
