Revealing modes from controlling an off-optical axis conical diffraction laser

An off-axis, wide-field, diffraction-limited, reflective Schmidt Telescope

Off-axis telescopes with unobstructed pupils offer great advantages in terms of emissivity, throughput, and diffractionlimited energy concentration. For most telescope designs, implementation of an off-axis configuration imposes enormous penalties in terms of cost, optical difficulty and performance, and for this reason off-axis telescopes are rarely constructed. However, for the reflective Sch...

Optical Diffraction Radiation from a beam off a circular target

Conical diffraction: observations and theory

Conical refraction was produced by a transparent biaxial crystal of KGd(WO4)2 illuminated by a laser beam. The ring patterns at different distances from the crystal were magnified and projected onto a screen, giving rings whose diameter was 265 mm. Comparison with theory revealed all predicted geometrical and diffraction features: close to the crystal, there are two bright rings of internal con...

An Off-Axis Neutrino Beam

1 Problem A typical high-energy neutrino beam is made from the decay of π mesons that have been produced in proton interactions on a target, as sketched in the figure below. Suppose that only positively charged particles are collected by the " horn ". The main source of neutrinos is then the decay π + → µ + ν µ. 1. Give a simple estimate of the relative number of other types of neutrinos than ν...

An Off-axis Model for Grb 031203

The low luminosity radio emission of the unusually faint GRB 031203 has been argued to support the idea of a class of intrinsically sub-energetic gamma-ray bursts (GRBs), currently comprising two members. While low energy GRBs probably exist, we show that the collective prompt and multiwavelength observations of the afterglow of GRB 031203 do not necessarily require a sub-energetic nature for t...