Tailoring light intensity along caustic trajectories.

A current challenge in a caustic beam design is to tailor the intensity distribution along the curved trajectory. To address this matter, we present a robust theoretical framework that relates the propagated complex wave field amplitude with the input spectral signal encoded onto a spatial light modulator which is suitable for fold-type monotonic trajectories as well as for cusp-type nonmonotonic trajectories. Specifically, we derive a general closed-form expression that relates the field amplitude along the beam trajectory with the spectral amplitude and the third derivative of the spectral phase for both monotonic and nonmonotonic curved trajectories.

Abruptly autofocusing beams from phase perturbations having forced symmetry.

A controllable manipulation of the energy distribution of caustic beams possessing rectangular symmetry is presented. The beams are designed from the spectral phase by adding a linear and/or quadratic perturbation having forced symmetry. This approach breaks the overall caustic structure into branches, allowing a fully controllable displacement of each branch.

Nonsymmetric curved beams within a symmetric caustic skeleton.

Nonsymmetric curved beams having a symmetric caustic skeleton are presented. They arise from a finite jump in the symmetric spectral phase that breaks the symmetry of the beam intensity without altering its associated caustic curve. These nonsymmetric beams can be represented as a superposition of two caustic beams whose wave fields have well-defined even and odd symmetries with weight coefficients dependent on the phase jump.

Structured light illumination for order sorting in Echelle spectrometers.

We report on the operation of an echelle spectrometer under structured light illumination. Each diffraction order of the spectrometer is encoded with a certain periodic structure allowing for order sorting by numerical analysis after detection. In contrast to cross-dispersed echelle spectrometers, in this approach the orders overlap at the detection plane so that the spectral calibration can be performed easily with a single reference wavelength.

Caustic beams from unusual powers of the spectral phase.

Caustic optical beams arising from a spectral phase whose power lies in an unusual range of values less than two are presented. Unlike what happens for conventional phase powers greater than two, it is feasible to generate caustic structures having properties that do not follow the established sorting. For instance, an asymptotic cusp caustic beam having a cusp point at infinity is demonstrated.