Coherent | Date: 2016-11-10
The method of and device for cutting brittle materials with tailored edge shape and roughness are disclosed. The methods can include directing one or more tools to a portion of brittle material causing separation of the material into two or more portions, where the as-cut edge has a predetermined and controllable geometric shape and/or surface morphology. The one or more tools can comprise energy (e.g., a femtosecond laser beam or acoustic beam) delivered to the material without making a physical contact.
Coherent | Date: 2015-08-19
Laser-machining apparatus includes a carbon monoxide (CO) laser emitting a beam of laser-radiation having forty-four different wavelength components and optical elements for delivering the radiation to workpiece. An acousto-optic modulator is provided for modulating the beam on the workpiece. A birefringent plate is provided in the beam transported to the workpiece for randomly polarizing radiation incident on the workpiece. A minimum distance of the workpiece from the laser, and the number of different-wavelength components in the laser beam provides that no optical isolator is required for preventing feedback of radiation into the laser.
Coherent | Date: 2015-09-01
An apparatus for generating and amplifying laser beams at approximately 1 micrometer wavelength is disclosed. The apparatus includes an ytterbium-doped gain-crystal pumped by an ytterbium fiber-laser. The fiber-laser enables a pump wavelength to be selected that minimizes heating of the gain-crystal. The apparatus can be configured for generating and amplifying ultra-fast pulses, utilizing the gain-bandwidth of ytterbium-doped gain-crystals.
Agency: GTR | Branch: EPSRC | Program: | Phase: Training Grant | Award Amount: 4.16M | Year: 2014
Recently, an influential American business magazine, Forbes, chose Quantum Engineering as one of its top 10 majors (degree programmes) for 2022. According to Forbes magazine (September 2012): a need is going to arise for specialists capable of taking advantage of quantum mechanical effects in electronics and other products. We propose to renew the CDT in Controlled Quantum Dynamics (CQD) to continue its success in training students to develop quantum technologies in a collaborative manner between experiment and theory and across disciplines. With the ever growing demand for compactness, controllability and accuracy, the size of opto-electronic devices in particular, and electronic devices in general, is approaching the realm where only fully quantum mechanical theory can explain the fluctuations in (and limitations of) these devices. Pushing the frontiers of the very small and very fast looks set to bring about a revolution in our understanding of many fundamental processes in e.g. physics, chemistry and even biology with widespread applications. Although the fundamental basis of quantum theory remains intact, more recent theoretical and experimental developments have led researchers to use the laws of quantum mechanics in new and exciting ways - allowing the manipulation of matter on the atomic scale for hitherto undreamt of applications. This field not only holds the promise of addressing the issue of quantum fluctuations but of turning the quantum behaviour of nano- structures to our advantage. Indeed, the continued development of high-technology is crucial and we are convinced that our proposed CDT can play an important role. When a new field emerges a key challenge in meeting the current and future demands of industry is appropriate training, which is what we propose to achieve in this CDT. The UK plays a leading role in the theory and experimental development of CQD and Imperial College is a centre of excellence within this context. The team involved in the proposed CDT covers a wide range of key activities from theory to experiment. Collectively we have an outstanding track record in research, training of postgraduate students and teaching. The aim of the proposed CDT is to provide a coherent training environment bringing together PhD students from a wide variety of backgrounds and giving them an appreciation of experiment and theory of related fields under the umbrella of CQD. Students graduating from our programme will subsequently find themselves in high-demand both by industry and academia. The proposed CDT addresses the EPSRC strategic area Quantum Information Processing and Quantum Optics and one of the priority areas of the CDT call, Towards Quantum Technologies. The excellence of our doctoral training has been recognised by the award of a highly competitive EU Innovative Doctoral Programme (IDP) in Frontiers of Quantum Technology, which will start in October 2013 running for four years with the budget around 3.8 million euros. The new CDT will closely work with the IDP to maximise synergy. It is clear that other high-profile activities within the general area of CQD are being undertaken in a range of other UK universities and within Imperial College. A key aim of our DTC is inclusivity. We operate a model whereby academics from outside of Imperial College can act as co-supervisors for PhD students on collaborative projects whereby the student spends part of the PhD at the partner institution whilst remaining closely tied to Imperial College and the student cohort. Many of the CDT activities including lectures and summer schools will be open to other PhD students within the UK. Outreach and transferable skills courses will be emphasised to provide a set of outreach classes and to organise various outreach activities including the CDT in CQD Quantum Show to the general public and CDT Festivals and to participate in Imperials Science Festivals.
Coherent | Date: 2016-07-11
In a line projector a diode-laser beam having an elliptical cross-section is projected onto a Powell lens which spreads the beam to form a line of light. Distribution of power along the line of light is adjusted by rotating the diode-laser beam with respect to the Powell lens.
Coherent | Date: 2016-04-07
A method is disclosed evaluating a silicon layer crystallized by irradiation with pulses form an excimer-laser. The crystallization produces periodic features on the crystallized layer dependent on the number of and energy density ED in the pulses to which the layer has been exposed. An area of the layer is illuminated with light. A microscope image of the illuminated area is made from light diffracted from the illuminated are by the periodic features. The microscope image includes corresponding periodic features. The ED is determined from a measure of the contrast of the periodic features in the microscope image.
Coherent | Date: 2016-04-13
Plane-polarized laser-radiation from a laser-source is converted to circularly polarized radiation by a quarter-wave plate. The circularly polarized radiation is input into a hollow-core fiber for transport to a point of use. The transported radiation is converted back to plane-polarized radiation by another quarter-wave plate between the fiber and the point of use.
Coherent | Date: 2016-01-20
In a laser line projection apparatus, six spaced-apart unpolarized laser-beams are plane-polarized with low loss by a combination of a thin-film polarizer, a reflector, and two polarization rotators. Two beams are polarized in each of three polarization-orientations. Two of the polarization-orientations are orthogonally aligned with each other in P and S orientations. The other polarization-orientation is non-orthogonally aligned in an intermediate orientation. The beams are intensity-homogenized and projected into a line of radiation. Any point on the line of radiation is formed from rays with an angular distribution of polarization-orientation from S to P through the intermediate orientation and back to S through the intermediate orientation.
Coherent | Date: 2016-12-21
Method for composing an output video signal (S_(o)) from a plurality of input video signals (Si1, Si2, Si3 ... Sim), which comprise respective input frame sequences (S_(i1)[n], S_(i2)[n], Si_(3)[n] ... S_(im)[n]) with a number of pixels for each input frame associated with an input resolution (R_(i1), R_(i2), R_(i3 ...) R_(im)), which comprises determining the spatial surface on a three-dimensional virtual space associated with each pixel; establishing a visualization point (X0,Y0,Z0) and a visualization window in the three-dimensional virtual space; calculating an associated threshold pixel density for the pixels in the visualization window; determining combinations of input frames, the projections of which are at least partially overlapping in the visualization window; and selecting the frame of each combination of frames which projected on the visualization window has a pixel density in the entire overlapping part greater than or equal to the threshold pixel density or, in the absence thereof, selecting the frame which projected on the visualization window has a greater pixel density in order to form the output frame part which is overlapping.
Coherent | Date: 2016-01-04
The present disclosure is directed to simultaneously controlling peak pulse power and pulse energy in gas-discharge lasers. In an aspect, a radio-frequency power supply that is coupled to a gas-discharge laser is turned ON to initiate delivery of a laser pulse. The radio-frequency power supply is modulated ON/OFF to maintain the amplitude of the laser pulse at about a desired or prescribed value. Further, the radio-frequency power supply is turned OFF to terminate delivery of the laser pulse when the accumulated energy reaches reached a predefined energy threshold value.