We developed a protocol to measure the bending rigidity of filamentous rod-shaped bacteria. Forces are applied with an optical trap, a microscopic three-dimensional spring made of light that is formed when a high-intensity laser beam is focused to a very small spot by a microscope's objective lens. To bend a cell, we first bind live bacteria to a chemically-treated coverslip. As these cells gro...

Vibratory communication in arthropods is a widespread phenomenon. Arthropods living on plants have been reported to use only dispersive bending waves in the context of prey-predator, competition, social and sexual interactions. Differences in signal structure have also been postulated to work as species recognition mechanisms and speciation agents. Using two identical laser Doppler vibrometers ...

Sheet-metal parts typically follow a unidirectional flow in the sheet-metal shop. In the first cutting stage, a large sheet is cut to different unfolded parts with a laser cutting machine. To avoid waste material different parts are combined on a sheet. Next, the 2D parts are transformed to 3D products with air bending. In this bending stage, timeconsuming set-ups between production layouts are...

Hollow glass waveguides with a 250-µm i.d. have been fabricated with a liquid-phase deposition technique that uses silica tubing as a base material. The losses of the 250-µm-bore guide measured at CO(2) laser wavelengths are as low as 2.0 dB/m. The straight losses for the hollow guides are in good agreement with theoretically predicted losses as a result of the nearly ideal structure of the gui...

The co-propagation of an intense particle beam with an ionizing laser beam in a working gas/plasma is considered. When the axes of the laser and particle beam are not aligned, then asymmetric plasma lensing results in a net dipole "eld acting on the particle beam. The particle beam can be steered or bent (as well as focused) by steering the laser. An analogy is made between the bending of the p...

Gamma-neutron activation experiments have been performed with relativistic electron beams produced by a laser wakefield accelerator. The electron beams were produced by tightly focusing ~spot diameter '6 mm) a high power ~up to 10 TW!, ultra-short (>50 fs) laser beam from a high repetition rate ~10 Hz! Ti:sapphire ~0.8 mm! laser system, onto a high density (.10 cm) pulsed gasjet of length '1.5 ...

Actively bent X-ray mirrors are important components of many synchrotron and X-ray free-electron laser beamlines. A high-quality optical surface and good bending performance are essential to ensure that the X-ray beam is accurately focused. Two elliptically bent X-ray mirror systems from FMB Oxford were characterized in the optical metrology laboratory at Diamond Light Source. A comparison of D...

a Photonics Research Group, Aston University, Aston Triangle, Birmingham, B4 7ET, U.K. Photonics Research Laboratory, Cyprus University of Technology, Cyprus Telephone: (+44)121-359-3611 ext. 4952 Fax: (+44) 121-359-0156 email: [email protected] ABSTRACT A series of LPGs was inscribed in photonic crystal fibre by a low repetition femtosecond laser system. When subjected to bending they w...

In this paper the delivery of high power Er:YAG laser pulses through a silica hollow core photonic crystal fibre is demonstrated. The Er:YAG wavelength of 2.94 µm is well beyond the normal transmittance of bulk silica but the unique hollow core guidance allows silica to guide in this regime. We have demonstrated for the first time the ability to deliver high energy pulses through an all-silica ...

The nonlinear refractive-index (n(2)) spectrum of ZnSe near the band gap (lambda(gap) approximately 450 nm) at 77 K was measured for the first time to our knowledge by using self-bending of a pulsed laser beam. The maximum nonlinearity, n(2) approximately 1.9 x 10(-8) cm(2)/W, measured by us is anomalously large, which cannot be explained by conventional thermally induced band-gap shrinkage.