Benefiting from a uniquely stable production environment – Optical Surfaces Ltd is recognised as one of the world’s finest manufacturers of solid and air spaced etalons.

Etalons are widely used in telecommunications, lasers, and spectroscopy to control and measure the wavelengths of light. Recent advances in fabrication techniques, developed by Optical Surfaces Ltd, has enabled the creation of a new generation of very precise tuneable Fabry–Pérot interferometers.

Dr Aris Kouris, sales director said “Working deep inside a chalk cliff, where temperature variation is negligible all year around, our skilled optical craftsmen can routinely create etalon pairs with ultra-low microroughness and surface accuracies that are better than lambda/300 peak to valley. As a result, we are the preferred supplier of matched etalon pairs to a growing group of discerning customers including a leading manufacturer of ultra-high resolution tuneable Fabry Perot interferometers”.

He added “Available in a range of shapes our etalons are designed for use at customer-defined wavelengths within the range 190 nanometres to about 2 microns. They are supplied with wedge angles of 5 minutes of arc for smaller diameters, rising in steps to a wedge angle of 40 minutes of arc for diameters from 70 – 170mm. Optical Surfaces etalons are available as standard in materials including UV grade Silica, Silicon and Germanium”.

For further information on ultra-high precision etalons for use in applications in interferometry, lasers and high-resolution spectroscopy please visit www.optisurf.com/index.php/products/etalons/ or contact Optical Surfaces Ltd. on +44-208-668-6126 / sales@optisurf.com.

Optical Surfaces Ltd is a leading manufacturer of high precision custom and prototype lenses for the most demanding camera, collimator, and optical imaging system applications. The company has extensive experience of producing high precision singlets, doublets, meniscus, cylindrical and aspheric lenses up to 600mm (24-inches) in diameter.

Large diameter high precision meniscus lens

From decades of producing large diameter custom lenses for leading research establishments, government institutions and industrial organisation worldwide – Optical Surfaces has built up an extensive range of test plates and tools to cover many lens sizes and radii. Customer specified noncircular lenses and air spaced lens assemblies are available on request.

Benefiting from a unique thermally stable manufacturing environment and working with high-stability materials such as Zerodur and Fused Silica, Optical Surfaces can routinely achieve a surface accuracy of better than lambda/20 p.v., surface roughness of less than 1nm rms and smoothness of 10/5 scratch/dig on large diameter lenses. Combining this world class surface quality with a range of low reflectivity AR coatings on supplied large diameter lenses enables researchers to achieve the leading-edge optical performance and efficiency required by even the most demanding experiments.

Optical Surfaces Ltd has produced high precision optics and optical systems from its ISO 9001-2015 approved manufacturing facility for more than 50 years and today is accepted as one of the world’s leading manufacturers of large diameter lenses.

The company’s 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 of large diameter, high precision lenses, particularly those with long path lengths, becomes quantifiable and reliable.

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

Optical Surfaces Ltd has developed a new modular approach enabling simple set-up of a larger diameter beam expander assembly aligned to your optical experiment. These pre-aligned modules enable researchers to undertake a complex 5-degrees of freedom set-up in a matter of minutes rather than days or even weeks.

Traditionally beam expanders have come as complete, pre-aligned mounted optical systems in an enclosure. While this approach provides a good beam expansion solution for optics up to 200mm diameter, above this an enclosed system solution becomes too large, too heavy, and too expensive. Drawing upon decades of designing and making high performance optical beam expanders – Optical Surfaces pre-aligned modules offer a time, space, and cost saving solution for beam expansion for optics up to 500mm diameter.

The modular beam expander assembly components supplied by Optical Surfaces include mounted primary and secondary mirrors that come pre-set to the “right” positions for your experiment, relative to a 25mm x 25mm, M6 standard optical table hole-pattern and both mirrors rotation will be factory pre-aligned and fixed.

Each customer will receive their beam expander mounted mirror modules with all freedoms of movement fixed giving you a very accurate start for alignment. Together with these mounted and fully pre-aligned pairs, three reference stops are supplied with each mount. These reference stops are precision machined to the exact diameters corresponding to the pre-aligned system in its finally fixed positions. The exact relative coordinates of the stop positions in relation to the M6 standard optical table hole-pattern for each modular beam expander are provided by Optical Surfaces. These reference stops reduce the required installation and alignment time to an absolute minimum. Any final tweaking adjustments necessary are typically minor if needed at all.

A high precision reference flat is included with each customer specified modular beam expander enabling quick and easy alignment to your optical experiment.

Optical Surfaces Ltd has been producing optical components and systems from its ISO 9001-2015 approved manufacturing facility for more than 50 years and are today accepted as one of the world’s leading manufacturers of beam expanders. For further information, or to discuss an easy alignment modular beam expander to match your optical experiment, please contact Optical Surfaces Ltd. on +44-208-668-6126 / sales@optisurf.com.

Optical Surfaces Ltd. has collaborated with the Institute of Plasma Physics & Lasers at the Hellenic Mediterranean University (Rethymno, Crete, Greece) to develop high quality customised optics, including off-axis parabolic mirrors, as key focusing elements for their ‘Zeus’ 45 TW ultrashort laser pulse system.

The Institute of Plasma Physics & Lasers (IPPL) is internationally renowned for its cutting-edge research in areas including laser matter / plasma interactions, pulsed power generated plasmas and modelling / simulation of these problems. IPPL is one of the access points of the National Research Infrastructure – HELLAS-CH.

Director of the IPPL Lab – Professor Michael Tatarakis said “The two new 76.14 mm diameter, 1008.7 mm focal length, hard dielectric coated mirrors are to replace damaged mirrors that Optical Surfaces made for us back in 2015. The damage is due to the natural impact of repeated highly energetic pulses (1018-1020 W/cm²) and the inevitable coating deterioration after extended high repetition rate use under such conditions. In cutting edge research, it is important to trust and collaborate with suppliers that have a good understanding of our research needs and can translate this into reliably producing optics that meet the high-quality demands of high energy applications. Certainly, reliable diffraction-limited optics such as those Optical Surfaces manufactures help us extend the frontiers of our fundamental research.”

Professor Tatarakis added “The intended application for these two new off-axis parabolic mirrors will be to explore new regimes in high repetition rate accelerated electron and ion beams with high stability via the interaction of the Zeus laser pulses with plasmas using gaseous targets”.

Benefiting from a highly skilled team of engineers and craftsmen, and a uniquely stable manufacturing environment, over the last 60 years – Optical Surfaces has established itself as a world leading producer of high precision off-axis parabolic mirrors. The company can routinely produce OAP mirrors with surface accuracy to lambda/20 (peak-to-valley) depending upon off-axis angles. Using proprietary polishing techniques Optical Surfaces can, depending on the surface accuracy required, achieve the natural limit to the off-axis angle of around 25-30 degrees and surface micro-roughness of less than 1 nm. A range of coatings is available for standard and custom components from metallic with or without protective overcoat to multilayer dielectrics and ultra-hard coatings.

Unlike standard parabolic mirrors, off-axis parabolic mirrors direct and focus incident collimated light at a specific angle, allowing unrestricted access to the focal point as well as reducing the size and minimising the weight of an optical design.

To learn more about the research interests and facilities at the Institute of Plasma Physics & Lasers please visit https://ippl.hmu.gr/en/home-en/.

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

Optical Surfaces Ltd has launched a new mounting system that provides a highly stable platform for wedged back off-axis parabolic mirrors.

Off axis parabolic mirrors can be produced by two distinct methods, as a standalone single optic or from a parent on-axis paraboloid. Produced by the parent method, wedged back off-axis paraboloids can be very accurately centred. In addition, the back of the wedged back off-axis parabolic mirror can be polished and used to define the optical axis direction which assists alignment. Until now, mounting a wedged back off-axis parabolic mirror has been a difficult and time-consuming task.

Ultra-high precision off-axis parabolic mirrors are however useless unless they are positioned with absolute precision and are stress-free. Optical Surfaces Ltd has developed the expertise to produce stress-free mounts tailored for use with a specific wedged back off-axis parabolic mirror thereby optimizing the optical performance of these useful optical systems.

Constructed in black anodized aluminium – Optical Surfaces wedged back paraboloid mounts provide a secure and stable platform for mirror diameters from 50mm to 200mm. Angular alignment about two axes is made by means of dual action adjusters that allow high resolution positioning. The correct rotational adjustment is pre-set by the factory. Using these tailored optimised mounts, it is possible to align a wedged back off-axis parabolic mirror rapidly and accurately.

Benefiting from a uniquely stable manufacturing environment, and a highly skilled team of engineers and craftsmen, Optical Surfaces is today the world leading producer of high precision off-axis parabolic mirrors. The company can routinely produce off-axis parabolic mirrors with surface accuracy to lambda/20 (peak-to-valley) depending upon off-axis angles. Using proprietary polishing techniques Optical Surfaces can, depending on the surface accuracy required, achieve the natural limit to the off-axis angle of around 25-30 degrees and surface micro-roughness of less than 1 nm. A range of coatings is available for standard and custom components from metallic with or without protective overcoat to multilayer dielectrics and ultra-hard coatings.

For further information on mounts tailored for wedged back off-axis parabolic mirrors please contact Optical Surfaces Ltd on +44-208-668-6126 or sales@optisurf.com.

Optical Surfaces Ltd is a manufacturer of large output beam expander optics enabling interferometers to be used for testing of large optical flats up to 600mm in diameter.

Large output beam expander modules from Optical Surfaces comprise an air-spaced lens doublet input coupled to a large spherical lens to increase the diameter of a collimated input beam (50 – 100mm) to a larger output beam (300 – 600mm).Designed to deliver low wavelength distortion and high transmission over specific wavelengths, these large output beam expander optics provide diffraction limited performance over their entire aperture.

Incorporating high precision lenses manufactured in Optical Surfaces uniquely stable manufacturing environment, the large output beam expander optics can achieve a typical wavefront distortion of better than lambda / 10. Available in 5x, 10x (standard) or customer specified fixed magnification configurations – each set of large output beam expander optics is designed to be easy to use and to provide accurate, unobstructed expansion of any collimated input light source.

Each large output beam expander is supplied in individual modules allowing you to optimally interface with your interferometer set-up. An interferogram and OPD map is supplied with every set of large output beam expander optics manufactured by Optical Surfaces Ltd.

Optical Surfaces Ltd has been producing optical components and systems from its ISO 9001-2015 approved manufacturing facility for more than 50 years and are today accepted as one of the world’s leading manufacturers of beam expanders.

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

Optical Surfaces Ltd is a leading provider of high precision optical components for terrestrial and spaceborne telescope spectrographs.

a Zinc selenide spectrograph prism

Spectrographs are the ‘go to’ scientific instruments used to study the chemical / physical conditions that exist through a cross-section of space. Combined with a terrestrial or spaceborne telescope a spectrograph can reveal the details that are stored in the spectral distribution of light from a distant star or galaxy.

Instrument performance matters in all scientific research, but none more so than in space exploration. New discoveries in space today are only possible using spectrographs that incorporate ultra-smooth optics able to collect the faintest light signals from distant astronomical entities.

With manufacturing and test facilities situated deep underground in an area excavated from solid chalk, temperatures in Optical Surfaces Ltd. production facility remain constant year-round and vibration is practically non-existent. These are important considerations when making, mounting and testing high precision telescope spectrograph optics. Benefiting from this unique stabilised environment Optical Surfaces Ltd has developed a reputation for designing, producing and testing large and demanding telescope spectrograph optics (aspherics, mirrors, prisms, lenses and flats) that would stretch the limits of conventional optical fabrication techniques.

Preparing the parent for an ultra-high precision spectrograph parabolic mirro.

Combining these natural advantages with a highly experienced team of optical designers, engineers, and production staff – Optical Surfaces Ltd. are regularly selected to supply ultra-high precision telescope spectrograph optical components by many international space research groups. Notable projects where Optical Surfaces Ltd. has supplied key optics for include the Narval stellar spectropolarimeter installed on the 2m Bernard Lyot Telescope in the French Pyrenees, the High-Resolution Optical Spectrograph (HROS) based on the 8m Gemini Telescope in Chile, the Fibre-fed Extended Range Optical Spectrograph (FEROS) at the European Southern Observatory (ESO) and the ESPaDOnS spectrograph at the Canada-France-Hawaii telescope (CFHT).

To read a case study please visit www.optisurf.com/index.php/spectrograph-record-near-ir-spectrum-stars-single-exposure/. For further information on telescope spectrograph optics please contact Optical Surfaces Ltd. on telephone on +44-208-668-6126 or email sales@optisurf.com.

Optical Surfaces Ltd. offer a range of optical mounts designed to mechanically support parabolic, spherical, and flat mirrors from 100 to 600mm (4 to 24 inches) in diameter.

Employing high precision optics in applications where optical stability is critical is pointless unless they are positioned with absolute precision and stress-free. To fulfil this need, Optical Surfaces designed the OS Series of optical mounts to overcome the ease of use and poor performance shortfalls of many general-purpose mounts.

For smaller diameter mirrors (100 – 254mm) you have a choice of four models of OS Mounts provide a secure and stable platform for your optical experiment. Two-axis angular alignment can be quickly achieved by means of dual action adjusters with fine screw and ultra-fine differential micrometre action. Using these mounts, you can rapidly align a mirror within a few arc seconds. Each mount comes with a baseplate to facilitate rapid and simple mounting onto an optical table or other experimental platform.

For secure and stable positioning of larger diameter mirrors (305 – 550mm) – Optical Surfaces offers four standard OS Series mounts. Angular alignment of larger diameter mounted mirrors is achieved about the vertical and horizontal axes over a wide range of angles. Using these mounts, it is possible to rapidly align a large diameter mirror within a few arc seconds. Each OS 300-600 mount comes with adjustable feet to facilitate rapid and simple mounting onto an optical table. A range of additional motorised options are available for OS 300-600 series mounts, for instance to facilitate remote operation in hostile environments or for use in limited space applications where manual adjustment may be difficult.

All OS Series Mounts are constructed in black anodised aluminium and are proven in labs worldwide to give long, trouble-free operation.

Optical Surfaces is also experienced in designing and supplying custom optical mounts for securely holding and allowing precise positioning of larger diameter, irregularly shaped or lightweighted mirrors.

For further information on easy-to-use, ultra-stable optical mounts please visit www.optisurf.com/index.php/products/product-6/mounts-and-mounted-optics/ or contact Optical Surfaces Ltd on +44-208-668-6126 / sales@optisurf.com.

Drawing upon decades of experience – Optical Surfaces Ltd. is regularly selected by leading laser research groups including AWE, ELI, LULI, and CLF Rutherford to provide ultra-smooth focusing mirrors and other related optics for the most demanding high-power laser applications.

Benefitting from a uniquely stable production facility based deep inside a chalk cliff, Optical Surfaces skilled engineering team are world renowned for producing off-axis parabolic mirrors with surface accuracy, surface microroughness and surface slope errors at the limit of what is possible.

Wayne Harris – Managing director of Optical Surfaces commented “Few companies in the world can produce off-axis parabolic (OAP) mirrors of sufficient quality to enable Petawatt and Zettawatt lasers to focus their massive energy down onto targets only a few microns in size. The 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”.

Continuing Mr Harris said “OAP’s 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 laser applications. Many optical and system designers favour OAPs as they often provide the most cost-effective answer without any compromise in performance and present the ideal solution to many high-power laser beam focusing applications”.

To learn more about ultra-smooth 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.

Optical Surfaces Ltd. is a leading international manufacturer of large diameter, ultra-smooth off-axis parabolic mirrors for demanding applications.

Looking to develop their next generation of ultra-high resolution holographic diffraction gratings – Wasatch Photonics (Logan, Utah, USA) commissioned Optical Surfaces Ltd. to manufacture two large diameter off-axis parabolic mirrors – key components in their production process.

Widely used as optical components to separate light into its component wavelengths, Wasatch Photonics’ holographic diffraction gratings are key components in spectrometers, hyperspectral imaging systems, spectral-domain optical coherence tomography, and other photonics technologies. Holographic gratings are typically generated by imaging a series of closely spaced parallel lines into a light-sensitive material using an interferometric set-up. Producing holographic diffraction gratings of spectroscopic quality requires a stable optical bench and laser as well as the highest quality optical components (mirrors, collimating optics).

Dr. Aris Kouris, Sales Director at Optical Surfaces Ltd said, “In order to produce diffraction gratings using a holographic method, you need to produce a reference collimated beam at a relative angle to another collimated beam. The two collimated beams interact to produce an interference pattern, which is recorded on the holographic recording medium. If an ultra-high-resolution grating is required, it is important that the two beams are extremely well collimated with little wavefront error. However, another parameter that is also important is the slope error, which is a measure of the ‘smoothness’ achieved on the surface form. This quality parameter is critical to produce very high resolution, low noise gratings using the holographic method.”

He added, “Originally Wasatch Photonics contacted us to manufacture two 152mm diameter off-axis parabolic mirrors to a high specification (better than Lambda/10 P-V at 633nm) and we did so. These optical components were required as part of a test project to produce ultra-high resolution holographic gratings of 140mm diameter. In early tests it became apparent that the Lambda/10 P-V surface accuracy alone was not sufficient to produce holographic gratings of sufficient quality. After consultation on the matter, we suggested that improving the slope errors on the mirrors might be beneficial. After Wasatch Photonics shipped back the two 152mm diameter mirrors, we re-worked them to the improved slope error targets. The improved off-axis parabolic mirrors resulted in the customer being able to produce great quality ultra-high-resolution holographic gratings”.

Dr Kouris concluded, “As a result of this successful trial – Wasatch Photonics recently placed a follow-up order with Optical Surfaces Ltd. to produce two new 420mm diameter off-axis parabolic mirrors of similar quality to enable them to produce even larger ultra-high resolution holographic gratings”.

These projects are an example of the collaborative development approach taken by Optical Surfaces in collaborating with key customers, a process which continues beyond delivery of the quoted product. According to Process Engineering Manager Andrew Clawson of Wasatch Photonics, “Validation of any component or tool that comes into our facility is an important part of our quality program and allows us to maintain high standards of quality from start to end of our manufacturing process. Working with a supplier like Optical Surfaces who shares our philosophy of ‘getting it right’ and continuous improvement makes this so much easier and gives us the confidence that we have the right partners to deliver on newer, bigger projects.”

For further information on large off-axis parabolic mirrors with diffraction-limited surface quality please visit www.optisurf.com/index.php/products/off-axis-paraboloids/ or contact Optical Surfaces Ltd. on +44-208-668-6126 / sales@optisurf.com.

Wasatch Photonics holographic gratings deliver high efficiency, low polarization dependence, and uniform performance over broad bandwidths (UV / Visible / NIR) and large clear apertures – all in a robust, field-tested package. Drawing upon multiple patented design technologies, Wasatch Photonics offers the flexibility to recommend the best transmission grating for your unique application. For further information please visit https://wasatchphotonics.com/product-category/gratings-and-diffractive-optics/.