Growing tuning ranges
Laser sensors are regarded as a market of the future in which tunable lasers will successfully occupy specific niches. The vision of inline process controls in industry is increasingly becoming reality.
Patients take it for granted. For pharmaceuticals manufacturers, it's a challenge. To ensure that pills always contain the same amount of active ingredient, the active ingredient must be distributed homogeneously throughout the starting material. To make sure that this is the case, random samples are examined using spectrometers. This procedure is also used when mixing the electrode material for high-voltage batteries, for quality assurance in food factories and for laboratory analyses in clinics, chemicals factories and research institutions. Laser spectroscopy in particular is being used in more and more areas and is driving sustained global growth in laser sensor systems. With average rates of seven percent per year, the market grew from EUR 440 million to EUR 573 million in the last four years. Analysts at Strategies Unlimited expect the market volume to be more than EUR 606 million in 2016.
Tunable lasers make analysis easier
Tunable lasers that cover broad ranges of wavelengths are useful when carrying out gas and material analyses. With lasers of this type, researchers can systematically record the absorption spectra of the materials. Background: Under the influence of the laser, molecules and atoms absorb radiation of a specific wavelength. This absorption behavior allows the atomic and molecular composition of samples to be accurately determined.
With tunable lasers, spectra can be recorded quickly and easily. The flexible lasers are also popular when determining and measuring quantum dots, micro-cavities and photonic crystals. Exhibitors such as Toptica Photonics, Coherent, Sacher Lasertechnik or the Lithuanian company Brolis Semiconductors offer a wide selection of tunable diode lasers with an extremely wide range of wavelengths and power outputs. New ones are being added all the time. The latest additions are green and yellow (316–675 nm) diode laser systems from Toptica. At LASER World of PHOTONICS 2015, the specialist presented new CTL (Continuously Tunable Laser) platforms with wavelengths ranging from 915 to 985 nm and from 1,530 to 1,620 nm Brolis is also steadily expanding its portfolio. Its specialty: tunable diode lasers in the mid-infrared range (1,800–3,000 nm) with 100 nm tuning intervals and minimal line distances.
Quite fittingly, Coherent calls its new high-performance dual wavelength laser “Chameleon” owing to its broad tuning range (680–1,300 nm). Its 1.4 W output makes it ideal for exciting fluorescent dyes. Together with ultra-high-resolution fluorescence microscopes, it should allow researchers deeper and more detailed insights into the building blocks of life.
Innovative quantum cascade laser paves the way towards inline spectroscopy
With an innovative quantum cascade laser, researchers at the Fraunhofer Institute for Applied Solid State Physics IAF and for Photonic Microsystems IPMS are looking to enter a new dimension of tunability. “It allows a new type of spectroscopy which will soon allow us to follow chemical reactions continuously in real time rather than in random samples, as before,” explained IAF researcher Dr. Ralf Ostendorf outside LASER World of PHOTONICS 2015. His team presented a first prototype there.
The tiny laser, which is small enough to fit in a person's hand, offers impressive performance. Thanks to a new micro-mechanical scanner mirror, wavelengths can be tuned very quickly—1,000 spectra per second are possible. Software from IPMS then compares these in real time with reference values in a database. Companies from the pharmaceuticals, chemicals and food sector have already expressed great interest in inline spectroscopy. However, they will need to be patient. A project subsidized by the EU's Horizon 2020 program has just begun. During the project, 18 European companies and research institutions are aiming to develop a market-ready quantum cascade laser. A pilot line will be developed by 2019.
Image source: Fraunhofer IAF, Toptica