Beam Collimators for MTF Optical Testing

Beam CollimatorsOptical Surfaces Ltd is a leading supplier of Beam Collimators tailored to enable precise Modulation Transfer Function (MTF) testing of your optical systems.

MTF is a trusted technique for objectively evaluating the image-forming capability of optical systems. Reflective beam collimators are mirror assemblies that take divergent or convergent incoming light rays and produce parallel light output. They can be used to replicate a target at infinity without parallax. As a consequence, reflective beam collimators are the device of choice for performing polychromatic MTF measurements over extended wavelength ranges.

The high stability and performance of Optical Surfaces reflective beam collimators is achieved using a zero expansion off-axis parabolic mirror, manufactured to better than lambda/10 p-v surface accuracy. The optics within the beam collimator, are secured by the use of stress-free mounts and come pre-aligned for optimum performance. The off-axis design of Optical Surfaces beam collimators produces no central obscuration thereby ensuring highly efficient transmission is obtained.

The all-reflecting design of Optical Surfaces beam collimators is achromatic and with aluminium / magnesium fluoride coatings can operate from the UV to the infrared without adjustment. Using zero expansion glass mirror substrates these beam collimators provide exceptional operational stability. Each system has an output port datum plane giving a defined distance to the focus. All Optical Surfaces beam collimators provide a 20mm field ensuring full compatibility with standard black bodies.

A wide choice of options enables Optical Surfaces beam collimators to be tailored to exactly suit your MTF optical testing requirements. For further information on reflective beam collimators for MTF optical testing please visit www.optisurf.com/index.php/products/reflective-collimators/ or contact Optical Surfaces Ltd. on +44-208-668-6126 / sales@optisurf.com.

Challenging Aspheric Lenses for Nuclear Research

Optical Surfaces Ltd announces that it has received an order from the UK Atomic Weapons Establishment (AWE) for twelve ultra-fast focusing 370mm diameter aspheric lenses for its Orion petawatt laser research facility.

World-class expertise and cutting-edge science, engineering and technology lie at the heart of AWE work, spanning the life cycle of nuclear warheads from initial concept and design, to final decommissioning and disposal.

Challenging Aspheric Lenses for Nuclear Research

Image curtesy of AWE

The Orion laser facility is used to conduct research into high energy density physics phenomena, which occur at the heart of a nuclear explosion or the interior of a star. Orion is used to generate matter many times denser than solid, similar to that found at the centre of a giant planet such as Jupiter. At temperatures in excess of 10 million degrees, Orion can replicate conditions found at the centre of the Sun. These phenomena cannot be found anywhere else on planet Earth.

The order is a repeat order for the key focusing elements supplied by Optical Surfaces Ltd to AWE in 2008. Replacement of the original lenses is required as coatings and lens material gets damaged over time due to very high energy density of the Orion laser.

Dr Aris Kouris, Sales director at Optical Surfaces Ltd commented “We are very pleased to again be selected by AWE to supply the replacement fast focusing aspheric lenses that lie at the heart of their Orion petawatt laser facility”. He added “The greatest challenge in producing these ultra-smooth optics relates mostly with the high asphericity of the lenses, arising from the short focal length required. The short focal length not only enables AWE to use a relatively compact vacuum chamber for its experiments but also to achieve a very high energy density at the point of focus. This high asphericity also imposes an additional difficulty in controlling the demanding requirements associated with the lens wavefront gradients specification.

For further information about the Orion petawatt laser facility at AWE please visit http://awe.co.uk/what-we-do/science-engineering-technology/orion-laser-facility/

For further information on aspheric lenses for high energy laser research please visit https://www.optisurf.com/index.php/products/aspheric-lenses/ or contact Optical Surfaces Ltd. on +44-208-668-6126 / sales@optisurf.com

Athermalised Beam Expanders for Challenging Applications

For beam focusing applications in environments subject to wide temperature variation, Optical Surfaces Ltd. is able to produce athermalised beam expanders that deliver stable high performance.

Beam ExpandersOptical Surfaces athermalised beam expanders are based upon a Dall-Kirkham off-axis mirror design that incorporates INVAR elements to provide thermal stabilisation. In addition, to better control thermal behaviour, the off-axis mirrors in the athermalised beam expanders have a short focal length resulting in a very robust assembly which is less sensitive to temperature changes. As a result, high optical performance is maintained over a wide range of temperature (-40° C to +50° C).

Benefiting from an off-axis design, Optical Surfaces athermalised beam expanders provide an unobstructed output and highly efficient transmission. The reflective design of these beam expanders is achromatic and with aluminium coatings can operate from UV to far IR without adjustment or internal realignment. Each athermalised beam expander is housed in an aluminium housing with provision for fixing to an optical table. Alignment aids are provided to ensure correct beam pointing. Standard beam expanders have fixed magnification. Variable magnification beam expanders can be supplied with interchangeable primary mirrors. An interferogram and OPD map is supplied with every athermalised beam expander manufactured by Optical Surfaces.

For further information on athermalised beam expanders please visit click here or contact Optical Surfaces Ltd. on +44-208-668-6126 / sales@optisurf.com.

Off-Axis Paraboloids Enhance Laser Power Density

Optical Surfaces Ltd. reports on increased demand from high power laser research groups around the world for off-axis paraboloid mirrors to be used as the primary focusing element for their Petawatt laser beam lines.

Enhance Laser Power Density

Off-axis paraboloids offer the advantage of an unobstructed aperture and access to the focal plane. In addition, due to their completely achromatic performance, they are especially suitable for broadband or multiple wavelength applications.

Using proprietary production techniques, and benefiting from a uniquely stable manufacturing environment, Optical Surfaces highly experienced and skilled engineering team are able to produce fast focusing off-axis parabolic mirrors with unmatched surface accuracy, surface quality and surface slope errors.

Dr Aris Kouris of Optical Surfaces Ltd commented “Few companies in the world are able to produce off-axis paraboloids of sufficient quality to enable Petawatt lasers to focus their massive energy down onto targets only a few microns in size. Laser-plasma interactions under these conditions can produce energetic beams of electrons and protons as well as bright, coherent sources of X-rays enabling researchers to address fundamental questions in astrophysics and plasma physics”.

Mounted Off-Axis Mirrors for Intense Laser Interaction Studies

He added “In recent years we are honoured to have been selected by world leading high power laser research groups including AWE, ELI, LULI and CLF Rutherford as well as a growing number of academic centres of excellence to provide key off-axis focusing mirrors and other related optics”.

For further information on off-axis paraboloid mirrors for high energy laser research please visit https://www.optisurf.com/index.php/products/off-axis-paraboloids/ or contact Optical Surfaces Ltd. on +44-208-668-6126 / sales@optisurf.com

OSL Optics to help unlock the secrets of Jupiter’s Icy Moons

Optical Surfaces Ltd. (OSL) announces selection by Hensoldt Optronics GmbH, formerly Airbus (Oberkochen, Germany) to supply key precision optics for optical testing the Ganymede Laser Altimeter (GALA), one of 10 scientific instruments on-board the JUICE (Jupiter Icy Moon Explorer) mission.

JUICE Mission of Jupiter

JUICE mission artist’s impression (courtesy: ESA)

The JUICE mission is part of the European Space Agency (ESA) cosmic vision programme and its objective is to study Jupiter’s plasma environment and the three icy moons Ganymede, Europa and Calisto. The JUICE spacecraft will be launched in 2022 on an Ariane 5 rocket. After its 8 year voyage it will enter an orbit around Jupiter. During the following three years the orbit will be gradually adjusted and after several fly-bys at Callisto, Europa and Ganymede the spacecraft will reach its final orbit around Ganymede. GALA will be used to determine the topography and time dependent shape of the moon by a direct laser altimetry approach.

UICE mission in Jupiter orbit

Strong electron field faced by JUICE mission in Jupiter orbit.

The GALA instrument is composed of three units: a transceiver unit, a laser electronics unit and an electronics unit all designed to withstand the challenging environment of Jupiter. At the heart of the transceiver unit is a lightweight Ritchey–Chrétien telescope incorporating precision optics capable of providing topographical vertical resolution of less than 5 metres and measure radial tidal deformations of the moons ice shell with an absolute accuracy of less than 0.03.

Because of its international reputation for supplying outstanding mounted optics for telescope systems and instruments, Hensoldt selected Optical Surfaces Ltd. to manufacture and supply a 550 mm diameter off-axis parabolic mirror and two identical folded flat mirrors (600 mm diameter) for optical verification testing of the Ritchey–Chrétien telescope in the GALA instrument.

Dr Aris Kouris, Sales Manager for Optical Surfaces Ltd. commented “To be chosen as a supply partner to help enable the JUICE mission is a great honour. Drawing upon our many decades experience in building telescope systems, we were able to propose a solution to overcome the considerable difficulties posed by the manufacture and testing of the high precision optics”.

For further information on high performance beam expanders please click here or contact Optical Surfaces Ltd. on +44-208-668-6126 / sales@optisurf.com.

Optical Surfaces Ltd Reports on Program of Investment

Program of InvestmentOptical Surfaces Ltd (Kenley, UK), a leading producer of ultra-high precision optics and optical systems, reports on an ongoing program of investment in new staff and facilities following consistent growth in sales over the last 3 years.

Dr Aris Kouris, Sales Director commented “Lead by increased international demand for challenging one-off’s and batches of high precision optics from the fundamental physics, astronomy and defence communities in particular we have achieved over 60% growth in the last 3 years. As a customer-focused company we elected to reinvest some of this success into new staff and also enhancing our already comprehensive test facilities with a new 600mm aperture Fizeau interferometer and development of new space for quality assurance”.

He added “I would like to take this opportunity to welcome our latest two new trainee optical technicians to Optical Surfaces. Danny Austin, a skilled machine operator, is currently being trained in polishing of large optical flats, windows and lenses. Drawing upon his experience in quality control, Enoch Wilcox has started his training in our optical smoothing team”.

For further information on Optical Surfaces Ltd please contact the company on +44-208-668-6126 / sales@optisurf.com.

Beam Compressor for Magdalena Ridge Observatory Interferometer

Optical Surfaces Ltd. has been selected by the Magdalena Ridge Observatory (Socorro, New Mexico, USA) to produce an ultra-stable 7.5x off-axis beam compressor that will form a key beam transfer element in the facility’s optical interferometer.

When completed the Magdalena Ridge Observatory Interferometer (MROI) will be one of the world’s most powerful optical-infrared interferometers, dedicated to high resolution imaging of all types of astronomical objects. The objects that will be observed with the MROI will include many types of nearby stars, including direct observations of the radial pulsations of Cepheid variable stars and surface features on giant stars, to imaging of the brightest active galactic nuclei. In its initial phase, the MROI will consist of three 1.4m diameter telescopes. The telescopes will be moveable between sets of discrete foundations, allowing baselines (inter-telescope spacing) between 7.5m and 347m in length. The MROI is projected to be able to produce an angular resolution of 0.6 milli-arcsecond at 1-micron wavelength.

Magdalena Ridge Observatory

Aris Kouris, Sales Director at Optical Surfaces Ltd, commented “We are delighted to have been selected for this prestigious international astronomical project. Optical Surfaces beam compressors incorporate high precision off-axis mirrors which provide an unobstructed output and highly efficient transmission. Beam compressors are the optical tool of choice for decreasing the diameter of a collimated input beam to a smaller collimated output beam. The reflective design of our beam reducers is achromatic and with protected silver coatings can operate from VIS to far IR without adjustment. However, located at an elevation of 10,600 feet above sea level in the Magdalena Mountains, the MROI beam compressor will be subject to considerable variation in temperature. As a consequence, the design for our 7.5x beam compressor will incorporate INVAR elements tie bars to provide thermal stabilisation”.

Robert Ligon, Instrument Scientist at the Magdalena Research Observatory, said “To minimize diffraction effects from long distance propagation, starlight is collimated into a 95 mm diameter beam at the telescope for propagation through most of the relay system.

The beam compressor to be produced by Optical Surfaces is a key component of the system, allowing the 95 mm beam of starlight to be reduced in size for the final division among instruments. After installation of the first telescope and enclosure at the beginning of the summer, the arrival of the beam compressor will allow us to complete our first beam line and begin testing the interferometer beam train before the arrival of our second telescope.”

For further information on high precision off-axis beam compressors and beam expanders please visit https://www.optisurf.com/index.php/products/laser-beam-expanders/ or contact Optical Surfaces Ltd. on +44-208-668-6126 / sales@optisurf.com.

The Magdalena Ridge Consortium Inc. was formed in January 1996 and the first design for the observatory was commissioned in 2000. In July 2004, a memorandum of agreement was signed with the Cavendish Laboratory of the University of Cambridge, UK for the design of the Magdalena Ridge Observatory Interferometer (MROI). The Magdalena Ridge Observatory (MRO) is a multi-use research and educational observatory operated by the New Mexico Institute of Mining and Technology (NMT) with offices located on the NMT campus in Socorro, New Mexico, USA. For further information please visit http://www.mro.nmt.edu/

Fizeau Interferometer for Testing Very Large Diameter Flats

Optical Surfaces Ltd has developed a 600mm Fizeau interferometer enabling it to now offer quality testing of flats in a single aperture up to 600mm in diameter. This is a capability that only a few optical testing and manufacturing centres around the world possess.

Fizeau Interferometer

Housed in an ultra-stable testing environment, this interferometric set-up will allow direct qualification of larger flat mirrors up to 600mm diameter by testing them directly over their complete aperture without the need to use time-consuming combination methods. This new capability increases confidence in measurement accuracy and data analysis while minimising potential errors and the time taken to complete the quality testing.

As a producer of ultra-high precision optics and optical systems for over 50 years, Optical Surfaces is acknowledged as a leading manufacturer of large, high precision reference / transmission flats and mirrors (coated flats) to research establishments, national standards laboratories and organisations worldwide. This is now complimented by the new interferometric testing facility, which will enable Optical Surfaces to reliably provide even more accurate test data on its reference and transmission flats up to 600mm (24 inches) in diameter.

The company’s ISO 9001-2008 approved manufacturing workshops and test facilities are deep underground in a series of tunnels excavated in solid chalk. This provides an environment where temperature is naturally stable and vibration is extremely low. With such stable conditions testing, particularly with long path lengths, becomes quantifiable and reliable.

Working with highly-stable technical materials such as, Fused Quartz and Zerodur, Optical Surfaces is able to routinely achieve a surface accuracy of better than lambda/20 p.v. and surface roughness of less than 1nm on reference and transmission flats up to 600mm in diameter. In addition to standard flats, Optical Surfaces offers special options for non-circular shaped flats, higher surface accuracy / quality, precision mounts, light-weighted options and an extensive range of coatings for demanding applications. All reference flats from Optical Surfaces Ltd. come with full quality testing assurance.

For further information contact Optical Surfaces Ltd. on +44-208-668-6126 / sales@optisurf.com.

Mounted Off-Axis Mirrors for Intense Laser Interaction Studies

Optical Surfaces Ltd. has received an order from Strathclyde Intense Laser Interaction Studies (SILIS) Group, from University of Strathclyde (UK) for three ultra-high performance off-axis parabolic mirrors in special custom vacuum motorised mounts.

Mounted Off-Axis Mirrors for Intense Laser Interaction StudiesThe mounted mirrors to be developed by Optical Surfaces Ltd. will be used on several beamlines of the facilities 350TW laser which is designed to support an extensive research portfolio in laser-plasma physics and multidisciplinary applications, with an emphasis on radiation sources and healthcare applications.

The SILIS Group are one of the main collaborators of SCAPA (Scottish Centre for the Application of Plasma-based Accelerators), an £8M+ state-of-the-art research facility. SCAPA houses laser systems, including a 350 TW laser (5 Hz, 25 fs) and 40 TW laser (10 Hz, 35 fs), and three radiation shielded bunkers, which have space for up to 7 beamlines. Each beamline is uniquely designed to focus on a specific category of laser-plasma interactions and secondary sources. A variety of photon and particle beams will be produced at SCAPA and utilised for multi-faceted R&D ranging from fundamental research (e.g. ionisation and plasma effects) to advanced university-scale applications arising from plasma-based light sources such as free-electron lasers, betatron radiation and inverse Compton scattering.

Three SCAPA beamlines will use Optical Surfaces ultra-high precision off-axis parabolic mirrors each manufactured with different focal lengths. The first one, produced with a long focal length (2000 mm), aims at investigating acceleration of high-quality electron and X-ray beams via underdense plasma and high intense laser interaction. The second one uses a pair of off-axis parabolic mirrors (1000 mm) as part of double plasma mirrors system to further enhance the contrast of the 350 TW SCAPA laser system. The third beamline, which uses the shortest focal length (210 mm) off-axis parabolic mirror, will be dedicated to the investigation of ultrahigh contrast, ultra intense laser-plasma interactions. This will facilitate research into the development and application of laser-driven ion beams.

Mounted Off-Axis Mirrors for Intense Laser Interaction Studies
Operating in a uniquely stable manufacturing environment – Optical Surfaces’ skilled production team is able to routinely produce precision off-axis parabolic mirrors that enable intense laser facilities to conduct ground-breaking research.

Dr Grace Manahan, a SCAPA and SILIS Group research associate said “In all of the beamlines, the quality of the produced/accelerated particles (electrons or ions) and X-ray radiation is highly dependent on the quality of the focus spot produced by the off-axis parabolas. This means that as the high-power laser beam propagates onto the parabola, it should experience virtually no wavefront distortion so that the focus spot is high quality (i.e. no astigmatism or distortion). The surface quality of the off-axis parabolic mirrors and the level of stability provided by their mountings are of vital importance in our supplier selection processes.

Dr Manahan added “We selected Optical Surfaces Ltd because we have colleagues that have already used their optics and their high recommendation gave me confidence on the quality we could expect. In addition, Optical Surfaces Ltd. were the only company that accommodated my series of modification requests and they accepted the challenges of manufacturing these challenging customised optics. During the whole selection process, though particularly in the design of a mirror mount that would be both vacuum compatible and motorised, we were delighted with the support provided by Optical Surfaces Ltd.”

Professor Dino Jaroszynski, Director of SCAPA, said “We are thrilled to have chosen very high quality components for optical setup. This will ensure good stability and reproducibility in experiments. Users will benefit with being able to undertake both long-term, systematic, experiments and shorter term exploratory experiments, which will give them the advantage of establishing good lines of research and pursuing their dreams with follow-on research that yields high impact results. SCAPA will be used by a broad range of users that are developing and applying radiation sources based on high power lasers.”

Optical Surfaces Ltd. has been producing optical components and systems for more than 50 years and is now accepted as one of the world’s leading manufacturers of parabolic mirrors for high energy laser research. The company’s ISO 9001-2008 approved manufacturing workshops and test facilities are deep underground in a series of tunnels excavated in solid chalk where temperature remains constant and vibration is practically non-existent. With such stable conditions testing, particularly with long path lengths, becomes quantifiable and reliable. Working with these natural advantages is a highly skilled team of craftsmen with a commitment to excellence in both product quality and customer service.

For further information on the Strathclyde Intense Laser Interaction Studies (SILIS) Group and SCAPA please visit http://silis.phys.strath.ac.uk/ and www.scapa.ac.uk/.

For further information on off-axis parabolic mirrors for high energy laser research please visit www.optisurf.com/index.php/products/off-axis-paraboloids/ or contact Optical Surfaces Ltd. on +44-208-668-6126 / sales@optisurf.com.

Precision Prisms Supplied for Habitable Planet Research

Optical Surfaces Ltd. reports first solar light results has been achieved by the SPIRou spectrograph* which is installed at the Canada-France-Hawaii Telescope (CFHT).

Precision PrismsChosen as a key supplier for this prestigious project – Optical Surfaces Ltd fabricated and delivered several key optical components of the SPIRou spectrograph, namely the twin ZnSe prisms and the Infrasil prism making the SPIRou triple-prism-train cross-disperser. The large Infrasil prism and the twin ZnSe prisms were manufactured to demanding specifications, in particular regarding transmission, wavefront error and scattered light.

The SPIRou spectrograph comprises a near infrared spectropolarimeter and high-precision velocimeter optimised for both the detection of habitable Earth twins orbiting around nearby dwarf stars and the study of forming sun-like stars and their planets.

SPIRou is an heritage instrument developed from the knowledge gained from previous successful spectropolarimeters (ESPaDOnS and NARVAL) and high-precision velocimeters (HARPS), and consists of a high-resolution cryogenic Echelle spectrograph fibre-fed from a Cassegrainian achromatic polarimeter and calibration system. This project is managed in the framework of an international consortium led by France and involving, in addition to the Canada-France-Hawaii Telescope (CFHT), Canada, Switzerland, Brazil, Taiwan and Portugal.

Spectral Graph

Dr Aris Kouris commented “Having supplied similar optics for the successful ESPaDOnS and FEROS projects, we have a proven record in manufacturing, mounting and testing precision optics for astrophysics projects”. He added “Our congratulations go out to the SPIRou team for collecting its first non-laboratory photons on November 15th and 16th by staring at the Sun for a couple of hours. This specific experiment allowed researchers to demonstrate that SPIRou reaches a spectral resolving power of 70000, and can measure polarimetric signatures down to sensitivities of 10ppm. Such outstanding performance can only be achieved utilising optical components of the highest quality”.

Optical Surfaces Ltd. has been producing optical components and systems for leading astrophysics research groups for more than 50 years. The company’s ISO 9001-2008 approved manufacturing workshops and test facilities are deep underground in a series of tunnels excavated in solid chalk where temperature remains constant and vibration is practically non-existent. With such stable conditions testing, particularly with long path lengths, becomes quantifiable and reliable. Working with these natural advantages is a highly skilled team of craftsmen with a commitment to excellence in both product quality and customer service.

For further information on demanding, high precision optics for astrophysics please contact Optical Surfaces Ltd. on +44-208-668-6126 / sales@optisurf.com.

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