Vacuum Compatible Beam Expanders

Optical Surfaces Ltd. (OSL) reports on growing demand for specialist Reflective Beam Expanders for high power lasers applications that can achieve higher power density through operating in a vacuum.

Vacuum Compatible Beam Expanders

Supplied optimised to individual customer specifications, all OSL vacuum compatible beam expanders incorporate smooth running mechanics that do not require lubrication, optical designs that avoid use of glues and cements that might outgas and sandblast finished metalwork that eliminates stray light without the need for anodising. On completion and performance testing – the beam condensers undergo scrupulous cleaning in a cleanroom environment where they are made ready for dispatch in specially developed packaging.

OSL vacuum compatible reflective beam expanders are aspheric mirror-based devices offering either beam expansion or reduction capabilities. Incorporating high precision off-axis mirrors, they provide an unobstructed output and highly efficient transmission. Reflective beam expanders use mirrors which have constant focal lengths, regardless of the light being focused. Thus, they can be used with collimated polychromatic light without the need of any fine focus adjustment. Available in a wide range of fixed or variable magnification configurations – the beam expanders are designed to be easy to use and to provide accurate, unobstructed expansion/contraction of any collimated input light source. They are also portable and can be used without the need for internal re-alignment.

Each beam expander is supplied housed in aluminium with provision for fixing to an optical table. Alignment aids are provided to ensure correct beam pointing. Manufactured to better than lambda/5 surface accuracy, the off-axis design produces no central obscuration and efficient transmission is obtained, unspoilt by spider diffraction patterns. An interferogram and OPD map is supplied with every product.

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

On-Axis Parabolic Mirrors

Optical Surfaces Ltd. offers a complete manufacturing and test capability to produce On-Axis Parabolic Mirrors up to 600mm (24-inches) in diameter. All on-axis parabolic mirrors are manufactured to customer specifications and are supplied with full surface quality test data.

On-Axis Parabolic MirrorsParabolic mirrors are the most common type of aspherical mirrors used in optical instruments. They are free from spherical aberrations, and thus focus the parallel beam to a point or point source to infinity. On-axis parabolic mirrors offer some advantages compared to off-axis paraboloids in that the achievable f-number is higher therefore allowing more energy to be concentrated. Generally also alignment of on-axis parabolic mirrors is less critical, thus easier.

Using proprietary production techniques – Optical Surfaces highly experienced and skilled production team are able to produce fast focusing on-axis parabolic mirrors with a surface accuracy of better than lambda/10 P-V and smoothness of 20/10 scratch/dig. Combining this excellent surface quality achieved during manufacturing with high reflectivity coatings enables researchers to achieve the high optical performance and efficiency required by even the most demanding experiments.

Optical Surfaces Ltd (www.optisurf.com) 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 high-precision on-axis parabolic mirrors for high power laser facilities, telescopes, LIDAR systems, beam collimators and expanders.

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 please click here or contact Optical Surfaces Ltd on +44-208-668-6126 / sales@optisurf.com.

High Precision Telescope Spectrograph Optics

Optical Surfaces Ltd. is a leading international supplier of high precision spectrograph optics for astronomical telescopes. Using a spectrograph enables researchers to study the chemical and physical conditions that exist through a cross-section of space. Combined with a land or space-based telescope a spectrograph can reveal valuable information from the spectral distribution of light from a distant astronomical object.

High Precision Telescope Spectrograph Optics

Preparing a large paraboloid parent

Benefiting from a unique facility, where temperatures remain constant year-round and vibration is practically non-existent, allows Optical Surfaces Ltd to produce and test demanding telescope spectrograph optics (aspheres, mirrors, prisms, lenses and flats) that stretch the limits of conventional optical fabrication techniques.

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 high precision telescope spectrograph optics. The company’s ISO 9001-2008 approved manufacturing workshops and test facilities are situated 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 high precision telescope spectrograph optics please contact Optical Surfaces Ltd. on telephone on +44-208-668-6126 / sales@optisurf.com. A selection of astronomical customer stories from around the world may be reviewed at www.optisurf.com/index.php/news/application-stories/

Ultra Stable, Rapid Alignment Mirror Mounts

Optical Surfaces Ltd designs and manufactures a wide range of mounts for use with mirrors (mirror mounts) to optimize their optical performance. Ultra-high precision mirrors are useless unless they are positioned with absolute precision and are maintained stress-free.

Gimbal mirror mounts z seriesThe OS-Z range of mirror mounts from Optical Surfaces Ltd. provide ultra stable, stress-free mounting and rapid alignment of off-axis parabolic, spherical and flat mirrors as well as wedge back and parallel back mirrors.

Constructed in black anodised aluminium, six models of OS-Z mount provide a secure, stable and compact platform for mirror diameters ranging from 90 to 250mm. Angular alignment can be made about two axes by means of dual action adjusters with fine screw and ultra-fine differential micrometre action. Using these mounts it is possible to align a mirror within a few arc seconds. Each mirror mount comes with a base plate. As an option to the standard two-axis gimbal micrometre-driven action, OS-Z mounts can be fitted with x-y-z linear stages if required. This option allows you to control positioning of mirrors in up to five-degrees of freedom.

For further information on ultra stable, rapid alignment mirror mounts please visit www.optisurf.com/index.php/products/product-6/gimbal-mirror-mounts/ or contact Optical Surfaces Ltd. on +44-208-668-6126 / sales@optisurf.com.

Relay Reflective Optics for Joint European Torus

Optical Surfaces Ltd. has received a sizeable order from the Culham Centre for Fusion Energy (CCFE) to manufacture the relay imaging reflective optics that will form part of two critical viewing diagnostic assemblies for the Joint European Torus (JET) when operating with a deuterium-tritium fuel mixture. The project is funded under the framework of EUROfusion**.

Infrared camera view of the inside of the JET fusion vessel (courtesy: EUROfusion)

Infrared camera view of the inside of the JET fusion vessel (courtesy: EUROfusion)

Comprising a series of large diameter (up to 500mm) ultra-smooth flat and spherical mirrors, some of which will have a very long radius of curvature, the relay imaging reflective optics will allow CCFE to monitor a number of physical and operational parameters within the JET fusion vessel with remote cameras from behind the 3m thick concrete shield wall. Knowledge of these parameters will ensure safe and smooth operation during JET’s planned campaign of fusion experiments using a deuterium-tritium fuel mixture. The relay imaging will be performed mainly with reflective optics because these are resilient to the hostile conditions that high energy neutrons and radiation present to them inside the Torus Hall.

CCFE is the UK’s national laboratory for fusion research. CCFE is owned and operated by the United Kingdom Atomic Energy Authority (UKAEA). CCFE hosts JET – the world’s largest magnetic fusion experiment – on behalf of its European partners. The JET facilities are collectively used by European fusion scientists, co-ordinated under EUROfusion.

Dr Tim May-Smith, Diagnostics Support Physicist/Engineer at CCFE, said “Selecting a supplier to manufacture the component optics was a very important decision because of the critical role that the relay cameras will play in the safe operation of JET. Optical Surfaces Ltd. was our selected supplier because of their experience and knowledge in the area of large optics, precision manufacturing expertise and value-for-money offered”.

Dr Aris Kouris, Sales Manager at Optical Surfaces Ltd. commented “We were pleased to be approached by CCFE to discuss the cost drivers and limitations in the manufacturing of the optics required by this project. This allowed us to exactly understand their needs and present a proposal that secured this prestigious order”.

Optical Surfaces Ltd. has been producing optical components, mounted optical components and systems for more than 50 years and is now accepted as one of the world’s leading manufacturers of large high-precision optics and optical systems for fusion 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 large high precision optics for fusion research please visit www.optisurf.com or contact Optical Surfaces Ltd. on +44-208-668-6126 / sales@optisurf.com.

For further information on JET visit http://www.ccfe.ac.uk/ and http://www.euro-fusion.org.

** The EUROfusion consortium is the organisational body of fusion energy research in Europe, funded by the Euratom Horizon 2020 programme and additionally from EU member states.

Laser Debris Shields

Optical Surfaces Ltd. is a leading supplier of laser debris shields (also known as protective windows or cover slides) to protect target-facing optics located in high-power laser facilities.

Laser Debris Shields

Laser debris shields help prevent damage to the focusing optics in laser beam delivery systems caused by dust, shrapnel and fragments originating from the target during laser processing. Optical Surfaces’ debris shields offer a cost effective solution to greatly extending the service life of typically expensive high power laser refractive and reflective optics.

Manufacturing high quality laser debris shields combines the dual demands of producing a precision wavefront on a flexible window with a high diameter to thickness ratio. Working with a wide range of glasses, which offer good homogeneity and transmission from the UV to the Near-IR, Optical Surfaces Ltd. is able to supply laser debris shields of the optimum shape and thickness to suit your laser delivery system and target facing optics.

Optical Surfaces Ltd.’s skilled and experienced craftsmen are able to routinely produce laser debris shields with high surface accuracy / quality (lambda/10 wavefront error and surface finish of 10/5), flatness and parallelism to <1 arc second. Automatic edging and bevelling on debris shields provides diamond edge finishes as per MIL-PRF-13830B, MIL-I-45208 & ISO-10110 specifications. High power laser anti-reflective coatings are available to optimise the transmission of your debris shields. For further information relating to high power laser optics and debris shields please visit www.optisurf.com/index.php/products/flats-and-windows/windows/ or contact Optical Surfaces Ltd. on +44-208-668-6126 or email sales@optisurf.com.

Optical Surfaces Delivers Parabolic Mirrors for Petawatt Laser

Parabolic Mirrors for Petawatt LaserOptical Surfaces Ltd. has delivered three challenging off-axis parabola of 175mm diameter to the UK’s prestigious Rutherford Appleton Laboratory.

Using a new technique – Optical Surfaces highly experienced and skilled production team manufactured a very fast parent F 0.6 parabola from which 3 fast focusing off-axis parabolic mirrors with surface accuracy of better than lambda/8 P-V, surface quality of 20/10 scratch/dig and surface slope error of lambda/10/cm P-V were produced.

The world class Gemini laser based at the Rutherford Appleton Laboratory, delivers Petawatt power laser pulses to targets only a few microns in size. The temperatures, pressures and magnetic fields at the laser focus reach levels that otherwise exist only inside stars, making Gemini a unique facility for scientists to conduct experiments that cannot be attempted anywhere else. Laser-plasma interactions under these conditions can produce energetic beams of electrons and protons as well as bright, coherent sources of X-rays and can also address fundamental questions in astrophysics and plasma physics. The laser focus is routinely generated with the use of precise parabolic focusing optics, which can only be made by a few companies in the world.

Parabolic Mirrors for Petawatt LaserThe order for the most recent focusing optic was tendered and awarded to Optical Surfaces Ltd. The key focusing mirror was particularly challenging as it was required to have a hole through the optic, on the focusing axis. This hole facilitates the co-propagation of a much longer focal length beam enabling a whole range of additional science to be explored.

Dr Aris Kouris of Optical Surfaces Ltd commented “To enable a range of new experiments on their Gemini laser, Rutherford ordered three off-axis paraboloids – one with a slanted conical hole in the centre and two without a hole. Due to tight operational constraints the delivery of the OAP with the hole had to be within a specific timeframe. For this reason, and due to the very demanding specification for this optic, we developed a new manufacturing technique that enabled us to speed up the manufacturing time of the parent parabola significantly. The method has successful and we managed to deliver it within the requested timeframe”.

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 high-precision optics for high power laser research facilities. 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 relating to Central Laser Facility at the STFC Rutherford Appleton Laboratory please visit http://www.clf.stfc.ac.uk/CLF/

For further information relating to diffraction limited parabolic mirrors please click here or contact Optical Surfaces Ltd by telephone on +44-208-668-6126 or email sales@optisurf.com.

High Precision Grisms for Euclid Mission to Map the Dark Universe

Optical Surfaces Ltd. has supplied the Laboratoire d’astrophysique de Marseille (LAM) (www.lam.fr) with polished substrates to manufacture the high precision grisms that lie at the heart of a Near Infrared Spectrophotometer designed to perform red shift measurements in the forthcoming Euclid space mission by the European Space Agency (ESA).

high-precision-grisms

LAM is one of the largest astrophysics public research institutes in France. It combines fundamental research in Astrophysics and the development of instrumentation for space and ground-based telescopes. The ESA’s Euclid space mission will study the dark universe. One of the on-board probes will be a Baryonic Acoustic Oscillations (BAO) device which will measure the red shift of millions of galaxies through their Near Infrared spectra. The Near Infrared Spectrophotometer instrument that forms part of the BAO has been designed to use low-resolution grisms in slit less mode to perform this massive red shift measurement.

A LAM spokesperson commented “The Near Infrared Spectrophotometer lies at the heart of making critical measurements on the Euclid mission. Consequently selection of a partner to supply the key optical components for the Spectrophotometer was a rigorous process. Our Near Infrared Spectrophotometer design requires 4 high precision grisms mounted on a wheel to allow us to measure galaxy red shifts in two spectral bands: 0.92-1.3 and 1.25-1.85 µm. Each grism is made a 140 mm Suprasil 3001 prism, manufactured from a 150 mm parallel plate onto which a grating is etched on the polished face and then the prism is manufactured”.

Dr Aris Kouris, sales manager for Optical Surfaces Ltd. commented “We are pleased to have produced the substrates to manufacture the grisms that will operate in the Euclid mission Near Infrared Spectrophotometer, and in particular the surface dedicated to the grating.. Apart from high surface accuracy (<10 nm RMS), our main challenge was to develop a polishing method to routinely achieve the extremely demanding near-zero sub-surface damage required by the project. In order to achieve this, the surfaces had to be kept completely clean and free of contamination while at the same time be kept virtualy scratch-free with a microroughness well below 1nm RMS. We found that any deviation from the required cleanliness and surface quality / roughness resulted in non-perfect surfaces after chemical etching, even if the surfaces look “perfect” prior to etching. It proved that only on virtually perfect surfaces could LAM make a grating to the standards that they require”. Optical Surfaces Ltd has been producing optical components, mounted optical components and systems for more than 50 years and is now accepted as one of the world’s leading manufacturers of high-precision optics and optical systems for space and ground based telescope applications. 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 high precision optics for space applications please contact Optical Surfaces Ltd. on +44-208-668-6126 / sales@optisurf.com.

High Precision Spherical Mirrors

High precision spherical mirrors produced by Optical Surfaces Ltd. are used in a huge variety of applications including Schlieren imaging, wind tunnels, observatory spectrographs, bubble chambers and to test hyperboloids (as Hindle spheres).

High Precision Spherical Mirrors

Benefiting from workshops and test facilities deep underground, where temperatures remain constant and vibration is practically non-existent, Optical Surfaces routinely produces high precision spherical mirrors in a wide range of materials and coatings. Typical achievable surface accuracy is better than lambda/30 p-v, surface quality 10:5 scratch dig and micro roughness less than 1.2nm RMS.

A typical example of these capabilities is a 1.3-metre diameter spectrograph spherical mirror supplied to the Royal Greenwich Observatory (UK) that was installed on the 2.5-metre Isaac Newton Telescope located at La Palma in the Canary Islands. This spectrograph contributed to obtaining the first observable evidence of the existence of black holes.

For further information on high precision spherical mirrors please visit www.optisurf.com/index.php/products/spherical-mirrors/ or contact Optical Surfaces Ltd. on +44-208-668-6126 / sales@optsurf.com.

Standard & Custom Design Off-Axis Paraboloids

In addition to supplying a range of standard specification Off-Axis Paraboloids (OAPs), Optical Surfaces Ltd. offers a consultative design and manufacture service to produce custom OAP’s to fulfil the most demanding and specialist applications.

off-axis-paraboloid-1Off-axis paraboloids, sometimes referred to off-axis parabolic mirrors or off-axis parabola, provide optical designers with an unobstructed aperture allowing complete access to the focal region as well as reducing the size and minimising the weight of a design. They are especially suitable for broadband or multiple wavelength applications due to their completely achromatic performance. All together these advantages produce a cost-effective solution for many optical design problems with no compromise in performance.

Production approved to ISO 9001-2008 the quality of OAPs from Optical Surfaces Ltd. is ensured using a range of interferometric and surface test measurements on all optics leaving the factory. The company offers a wide range of coatings to enable optimised OAP performance in applications including Beam Collimation / Expansion, FLIR testing, High power laser beam focusing, Astronomical spectrographs, Target projection, MTF referencing and MRTD testing.

Benefiting from a uniquely stable manufacturing environment, and over 50 years’ experience and expertise, Optical Surfaces OAPs are used by many leading research establishments and companies around the world.

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

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