Applications

Holography & Imaging

Holography is the generation of a 3D image using light. Apart from obvious applications in the arts, holography is also extensively used as security devices in currency and documents to prevent forgery due to their difficulty to reproduce. This is due to the phase information stored in the hologram that can only be accurately accessed by using the same light that created it. This need 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 is used to measure stress and strain in engineering structures, and holographic microscopy has pushed the resolution limit of optical microscopes down to the quarter wavelength range. Holography is also being hailed as the key technology behind the next wave of data storage. As it creates a 3D interference pattern, one can use the entire volume of the storage material, rather than just the surface, greatly increasing information density. It has also been theorised that gigabit per second write speeds and even greater read speeds could be achieved with such technology. 

Important to all these applications is the coherence length of the lasers used to create the hologram. The coherence length directly corresponding to the resolution of the holographic image. This mandates single frequency operation with excellent power stability. UniKLasers can offer this at a variety of wavelengths within a small self-contained package. 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 full colour holograms. This will allow for the creation of high-resolution full colour holograms in a small, robust package.

Metrology & Sensing

Metrology is the science of measurement and since the days of Maxwell it has been suggested that light should be used as the fundamental measurement device for distance and time. This is now the case and consequently lasers are relied upon to make some of the most accurate measurements on microscopic distances and times. Accurate measurements are essential to high level 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. This is essential to detect any unwanted deviations in thickness or detect defects such as holes and scratches. This can be done using laser interferometry that 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 errors in measurement. We also offer short wavelengths up to near UV allowing for higher resolution surface profiling. Long-term power and wavelength stability also reduces the need for calibration corrections over time and reduces errors when taking prolonged measurements. The Solo 698 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 difficult to discern, especially when background fluorescence is also considered. This demands the use of robust single frequency lasers with minimal spectral drift and power stability, particularly in analyses requiring long acquisition times or high resolutions. All of our lasers are specified with ±1.0 pm of spectral drift and <2.0% power variance over 8 hours of operation.

 
Our Solo 532 Series is a popular choice for versatile Raman spectrometers, whilst our Solo 1064 Series is specifically well-suited to analysis of biological samples where background fluorescence of organic origin 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 moving of small particles by using highly focused laser light. As light traverses the particle it experiences a change on refractive index and subtly changes its direction of travel. This exerts an opposite force on the particle, and if the particle is smaller than the light beam itself it 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. This has allowed scientist to easily isolate individual bacteria and viruses for study without mechanically interfering with them. Most biological samples are resistant to damage from near infrared radiation making our 1064nm the wavelength. 

Key to this technology and gaining a ‘firm grip’ on the particles is good power and pointing stability along with excellent beam circularity. With M2s of less than 1.05 in both axes and the compact and mechanically robust design of our BRaMMS technology, both our Solo 1064 Series and Solo 698 Series are ideally suited to this application. 

Quantum Technology

The emerging field of quantum technology promises radical developments in a variety of fields 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 in order to precisely manipulate the states of individual atoms. 

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UniKLasers has been working closely with those in the quantum industry to supply bespoke lasers at the specific wavelengths related to the exact atomic transitions they wish to target, including our Solo 780.24 Series for rubidium and Solo 698.4 Series for strontium. Our technology ensures excellent output power and wavelength stability during prolonged operation or during 8 hours of operation.

Short Range LiDAR

The use of short range LiDAR is becoming a useful 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 300-500m. This makes it extremely useful for measuring airflows over a short time scale, but with higher resolution and greater accuracy. This is important in such applications as wind tunnel profiling, turbulence at airports caused by smaller landscape anomalies such as buildings and optimising wind turbine location and performance, as well as air turbulence in front of a flying aircraft.

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In the wind turbine industry, the location of farm 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 environment: topography, vegetation etc. On land, this is expensive as high towers are erected with cup-anemometers at various heights, but if this is 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.