Applications

Holography & Imaging

Holography is the generation of a 3D image using light. Apart from its obvious applications in the arts, holography is also extensively used as security devices in currency and documents to prevent forgery, due to the difficulty in reproducing them. This is due to the phase information stored in the hologram, which can only be accurately accessed by the same light that created it. This requirement for highly accurate phase information is what mandates the use of lasers with excellent spatial and temporal coherence. 

Further applications of holography include Interferometry, which can be used to measure stress and strain in engineering structures, and Holographic Microscopy, which has pushed the resolution limit of optical microscopes down to the quarter wavelength range.

Holography is also being hailed as a key technology behind the next wave of Data Storage, as it creates a 3D interference pattern over the entire volume of the storage material, rather than just the surface, greatly increasing information density. It has been theorised that much faster read/write speeds could be achieved with this technology. 

Important to all these applications is the coherence length of the lasers used to create the hologram. The coherence length directly corresponds to the resolution of the holographic image. This requires single frequency operation with excellent power stability. 

UniKLasers can offer these specifications at a variety of wavelengths within a small footprint. We currently offer single frequency lasers in the red and green areas of the visible spectrum with our Solo 640 Series and Duetto 532 Series respectively; and are developing a blue system to complement these and facilitate high resolution, full colour holograms.

Metrology & Sensing

Metrology is the science of measurement. Since the days of Maxwell, it has been suggested that light should be used as the fundamental measurement for distance and time and this is now the case. Consequently, lasers are relied upon to make some of the most accurate measurements of distance and time, which are essential to a variety of areas, including engineering, surface profiling and the detection of low signal-to-noise events, such as gravitational waves.  

Integrated circuits form the bedrock of the Information Age. It is essential that the film thickness used during the photolithography stage is monitored and optimised and any unwanted deviations in thickness, or defects such as holes and scratches, are detected. This can be done using laser interferometry, which allows sub-wavelength resolution of these features. This same technique can be applied to other industries where sub-micron accuracy is required, such as optics and precision tooling. 

Our proprietary BraMMS Technology® ensures narrow linewidths and single frequency operation without sidebands, reducing the error in measurement. We also offer short wavelengths into the UV, allowing for higher resolution surface profiling. Long-term power and wavelength stability also reduces the need for calibration corrections and removes errors when taking prolonged measurements. The Duetto 532 Series and Solo 640 Series are a popular choice for many metrology, sensing and interometry applications.

Raman Spectroscopy

Raman spectroscopy is an important analytical technique in chemistry with emerging novel applications in biological sciences, facilitated by the inelastic scattering of photons by non-degenerate transitions in vibrational energy states of molecules. Raman scattering events are significantly more infrequent compared to Rayleigh scattering, whereby no change in energy of the photon occurs – the molecule returns to the state it occupied prior to photonic excitation.

The weak Raman effect is difficult to discern, especially when background fluorescence is also considered. This demands the use of robust, single frequency lasers with minimal spectral drift and high power stability, particularly in analyses requiring long acquisition times or high resolutions. All of our lasers are specified to ± 1 pm of spectral drift and < 2 % power variance over 8 hours of operation.

 
Our Solo 532 Series is a popular choice for versatile Raman spectrometers, while our Solo 1064 Series is specifically well-suited to analysis of biological samples, where background fluorescence must be eliminated.

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Our rare wavelengths, like 689 nm and 523 nm, act as enablers for some previously impossible research within this application.

Read our White Paper - Use of Single Frequency DPSS lasers in Raman Spectroscopy. 

Optical Manipulation

Optical manipulation, also known as optical tweezing or optical trapping, is a technique that allows the capture, trapping and movement of small particles using highly focused laser light. As light traverses the particle it experiences a change of refractive index and so slightly changes its direction of travel. This exerts an opposite force on the particle and, if the particle is smaller than the light beam itself, causes it to be ‘trapped’ in the centre of the beam. 

This has proved to be a highly useful tool in many fields, with everything from individual atoms, custom micro-machines and biological cells being manipulated using this technique. Scientists can now easily isolate individual bacteria and viruses for study without mechanically interfering with them, with most biological samples undamaged by NIR radiation, such as 1064 nm. 

Key to this technology and gaining a ‘firm grip’ on the particles is good power and pointing stability, along with excellent beam circularity. With M2 < 1.05 in both axes and the robust design of our BRaMMS technology, both our Solo 1064 Series and Solo 640 Series are ideally suited to this application. 

Quantum Technology

The emerging field of quantum technology promises radical developments in a variety of areas, including metrology, cyber security, and computing. Already many organisations rely on atomic clocks for their most accurate measurements of time and there is a large scale movement to take quantum gravimeters out of the lab and into the field, in order to monitor ice sheets and magma flows in volcanoes. All these technologies rely on accurately creating, manipulating and reading from quantum states of matter. This often requires lasers with excellent linewidth and stability, to precisely manipulate the states of individual atoms. 

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UniKLasers works closely with the quantum industry to supply narrow linewidth, high power lasers at the specific wavelengths related to the exact atomic transitions they wish to target, including our Solo 780.24 QT Series for Rubidium and Solo 698.4 QT Series for Strontium. Our technology ensures excellent output power and wavelength stability during prolonged operation.

Short Range LiDAR

The use of short range LiDAR is a growing sub-section of the Light Detection and Ranging market. Short range LiDAR is useful in making such measurements as wind speed, shear and turbulence over distances less than 500 m. This makes it extremely useful for measuring airflows over a short time scale, but with higher resolution and greater accuracy.

This is important in applications such as wind tunnel profiling, turbulence at airports caused by landscape anomalies, as well as air turbulence in front of a flying aircraft, and optimising wind turbine locations and performance, .

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In the wind turbine industry the location of windfarm placement, and indeed individual turbines, is key to maximising the efficiency of power generation. Consequently, measurements are needed that detail the wind characteristics at any point and how they are affected by the local environments, such as topography or vegetation.

On land this can be expensive, as high towers are erected with cup-anemometers at various heights, but at sea site surveying becomes even more difficult. Short range LiDAR systems are small and mobile, allowing them to be quickly and easily moved to different sites to assess the optimal positioning. Once in place, the short range LiDAR can be used to optimise the pitch of each turbine blade to maximise the efficiency given the approaching wind conditions.