An interview with Markus Mangold, Andreas Hugi and Markus Geiser (IRsweep - Innovation in sensing)

Date Announced: 05 Apr 2016

Markus Mangold, Andreas Hugi and Markus Geiser from IRsweep in Zurich, Switzerland explain their breakthrough in the optical sensing technology. IRsweep develops optical sensing solutions in the mid-infrared range - the fingerprint region of the most light molecules - offering high selectivity and speed combined with wide spectral coverage.  

What is dual comb spectroscopy?
Dual-comb spectroscopy was proposed as an intriguing form of Fourier transform spectroscopy technique using two multi-colored lasers. Its application for precision spectroscopy were awarded with the Nobel Prize in physics 2005. We use compact Quantum Cascade Laser (QCL) frequency combs to make the advantages of dual-comb spectroscopy accessible to a wider range of applications.  
The main advantages of this approach are high temporal and spectral resolution, over a broad spectral bandwidth without the need for any mechanical elements.
Dual-comb spectroscopy performed in the mid-infrared—where molecules have their strongest roto vibrational absorption lines— offers highest sensitivities and QCL frequency combs are an excellent source for such instruments.

What is IRsweep’s vision?
It is our vision to revolutionize optical sensing by making fast, selective and broadband laser spectroscopy available for a large range of applications. Highest product quality and customer satisfaction are among our core values.

Tell us more about your technology?
Frequency combs are lasers emitting many wavelengths at the same time, covering a broad spectral range of tens to a few 100 wavenumbers. The spectrum consists of very sharp, equally spaced lines. The exact equal spacing of the comb lines allows for the spectral resolution. The device operates in the mid-IR range where the strongest molecular absorption lines are located.  
So far, IR-frequency combs have been bulky, power-hungry systems, preventing them from spreading into a wide range of industrial applications. Instead, QCL frequency combs are very compact semiconductor devices, which are only a few mm long and electrically pumped.
When the frequency comb interacts with the sample substance, some colors of the laser are absorbed and the intensity of the transmitted light contains the necessary information to define the type and concentration of chemical species contained in the sample. The acquisition of all wavelengths is performed simultaneously with no moving parts required by heterodyning with a second frequency comb.    

Why did you start pursuing this technique?
This technique primarily combines four main important aspects of our vision to design this product on the first place. This technique allows the product to be fast, sensitive, high-bandwidth and highly resilient to industrial environment, due to absence of moving parts.
Besides dual-comb spectrometers, IRsweep is offering a new type of multi-pass absorption cell. What is new about this compared to the competition?
There is a range of manufacturers for multipass gas cells. Most cells target the market of > 30 m optical path. Those cells occupy a large footprint and contain a large gas volume as compared to the IRcell. We aim at different applications, where intermediate sensitivity is required with an optical path length of 1 to 4 m. In such applications, we can provide significantly lower sample volumes as well as smaller dimension cells than currently available.
The USP for IRcell is that it is robust, and compact in outer dimensions and inner volume. We want to provide our customers with convenience and improved performance.

What were the main challenges you had to overcome to make this technology work?
There are a number of properties of the mirror that have to be precisely engineered and manufactured in order to achieve a good optical properties of the transmitted beam. Part of that is also covered by our IP.  

Are there any limitations to the IRcell?
The sweet spot for such a cell design is at a path length of a few meters. At much longer path lengths, the competitive advantage in terms of small internal volume per path length degrades due to the IRcell’s geometrical scaling properties. However, there are other properties of the IRcell, which warrant its use also for longer paths, e.g. use in shock tubes, where the circular design is exploited, environments with large temperature swings or applications where the refocusing properties of the cell along the optical path are required.
You are also in the process of developing an IRspectrometer. Tell us more about that?
We are very passionate towards this project and are working really hard to have a first product placed by on the schedule in the fourth quarter of 2016.  
The IRspectrometer offers an unmatched combination of resolution, bandwidth and speed. It’s a high brightness laser spectrometer which will open up new application spaces which have not been accessible before. 

What are the future applications for the IRspectrometer?
The applications of the IRspectrometer are very exciting. Microsecond time resolution combined with large spectral bandwidth and high spectral resolution offer new possibilities for vibrational spectroscopy in research or in industrial applications. One example is the observation of protein folding, which is important for understanding diseases like Alzheimer. Industrial process analysis can also benefit from the high selectivity and multiple substances can be identified simultaneously – even when masked by a complex background matrix. The current solution in industrial processes is often an online gas chromatograph, which is orders of magnitude slower and consumable-intensive.
There are also different applications fields, like detection of hazardous substances, such as explosives and chemical weapon agents, where a fast response time and low number of false alarms is important.  

About IRsweep
Founded in 2014, based in Zürich, Switzerland, the company offers cutting edge optical sensing solutions based on semiconductor quantum cascade laser frequency combs in the mid-infrared spectral range. The company was awarded Venture Kick and the Volkswirtschaft-Stiftung Award in the year 2015.

Contact : sales@irsweep.com / +41 44 586 79 79

Contact

E-mail: swati.shinde@irsweep.com

Web Site: www.irsweep.com