This paper describes the design and simulation of the electron beam collimation system in the Linac Coherent Light Source (LCLS). Dark current is expected from the gun and some of the accelerating cavities. Particle tracking of the expected dark current through the entire LCLS linac, from gun through FEL undulator, is used to estimate final particle extent in the undulator as well as expected b...

This paper presents a UV (ultraviolet) lithography apparatus that utilizes an array composed of UV-LED (light emitting diode) collimation modules as a micro-patterning light source for PCB (printed circuit board) fabrication. To provide a uniform (non-uniformity > 90%) and collimated (FWHM < ±2°) exposure area, hexagonal light source modules are disposed in a hexagonal array. Each module is con...

Light emitted from single-mode semiconductor lasers generally has large divergence angles, and high numerical aperture lenses are required for beam collimation. Visible and near infrared lasers are collimated using aspheric glass or plastic lenses, yet collimation of mid-infrared quantum cascade lasers typically requires more costly aspheric lenses made of germanium, chalcogenide compounds, or ...

A transformation-optics wedge waveguide designed for the simultaneous collection and directional collimation of pulsed dipole radiation is described and tested with numerical simulation. Azimuthal compression of free space toward a narrow fan-shaped waveguide sector allows dipole pulse radiation in free space to be transformed into a directional non-dispersive pulse propagating within that sect...

In this paper a study of the directive gain enhancement obtained using a dielectric lens placed in the near field of radiating elements is discussed. The design and results of a single element patch antenna along with hemispherical and spherical lens radiating in C-band are detailed. The design has been accomplished using the 3D finite-element-method (FEM) electromagnetic EM simulator, HFSS, is...

An essential feature of SPECT imaging is collimation of gamma photons, allowing detection of only those photons propagating in the appropriate direction. Parallel beam collimators are widely used in different applications, because reconstruction is straightforward. Fan-beam collimators focus on a focal line parallel to the axis of rotation. For organs centered within the field of view this enha...

In this paper we show that the recently developed nanostructured gradient index (nGRIN) rod microlens can be utilised for the collimation of the beam generated by a vertical-cavity surface-emitting laser (VCSEL). The modelling of the nanostructured lens structure is performed using the finite difference time domain (FDTD) method with realistic nGRIN parameters and a Gaussian model of the light ...

This paper presents an in-plane hydrodynamically reconfigurable optofluidic microlens, which is formed by the laminar flow of two streams of a low-refractive-index fluid and two streams of a high-refractive-index fluid in the two microchannels connecting to an expansion chamber where the microlens finally forms. In the expansion chamber, the stream of high-refractive-index fluid, acting as core...