Community Research and Development Information Service - CORDIS

H2020

InSPECT Report Summary

Project reference: 644483
Funded under: H2020-EU.2.1.1.6.

Periodic Reporting for period 1 - InSPECT (Integrated Spectrometers for Spectral Tissue Sensing)

Summary of the context and overall objectives of the project

"Minimally-invasive image-guided procedures are becoming increasingly important in clinical practice. In a variety of procedures physicians lack reliable feedback on the type of tissue at the tip of their interventional device (needle, catheter, probes, etc…) to ensure they are at the right position before effecting the actual diagnosis or treatment. Spectral tissue sensing using compact photonic probes has the promise to be a valuable tool for screening and diagnosing purposes, e.g. for discriminating between healthy and tumorous tissue. Real-time tissue-characterization feedback to the physician during an intervention can significantly improve the outcome of diagnosis and treatment, and ultimately reduces cost of medical treatment. For a widespread adoption of spectral tissue sensing broadband miniature spectrometer devices should be become available at affordable cost, to make it commercially viable for also screening at point of care locations such as physicians’ offices and outpatient centers.

The InSPECT project enables the realization of photonic building blocks for low-cost miniaturized spectral tissue sensing devices. This involves the realization of a miniature broad-band solid-state light source and the realization of a miniature low-cost integrated spectrometer, both operating in the VIS/NIR from 400 to 1700nm. Two spectrometer devices will be developed: (i) a "microSpectrometer" based on the miniaturization and monolithic integration of diffractive dispersive elements and VIS+NIR photo-detectors in a small volume (cubic inch) device, and (ii) a "nanoSpectrometer", in which the spectrometer function is realized on a photonic integrated circuit (PIC) based on transparent SiO/SiN waveguide technology. For the latter multi-mode to single mode coupling structures will be realized in order to couple the output of a photonic probe to the spectrometer PIC. Ultimately, InSPECT will deliver the key photonics building blocks for low-cost miniature spectrometers, that will drive the widespread adoption of spectral sensing in applications that were not accessible before."

Work performed from the beginning of the project to the end of the period covered by the report and main results achieved so far

In the different work packages the following progress has been achieved during the first year of the project:

- Broad-band all-solid state based light source:
After a first literature study of possible candidates for luminescent materials in the infrared (NIR 700-1000nm and SWIR 1000-1700nm) we came up with a viable solution using luminescent ceramics (based on the (Lu,Gd)3-(Ga,Al)5-O12:Ce3+,Cr3+ system) and luminescent glasses (based on the GeO2:Bi system). Both materials show strong infrared emission upon excitation by standard visible LEDs. Together with conventional visible light LED solutions we are able to construct a single LED-based device covering the whole 400-1700nm spectral range. Future work concentrates on material system optimization and device assembly and packaging.

- microSpectrometer:
An overview of different spectrometer layouts for a compact broad-band microSpectrometer device has been studied and ranked with respect to user requirement specifications such as spectral coverage and SNR. We aim at using a modular approach, incorporating multiple gratings covering several subbands in the VIS-NIR-SWIR spectral range, in combination with two-dimensional VIS-NIR and SWIR sensors. Optical design of components (e.g. gratings, concave mirrors, Si and InGaAs sensors) has been started and first prototype evaluation shows promising results.

- nanoSpectrometer:
Creating a broad-band spectrometer on a photonic integrated circuit (PIC) imposes many challenges. First, the PIC wavelength selective components need to cover the full spectral range from 400-1700 nm. For this we worked on a new high contrast waveguide geometry, ultimately allowing for integration of multiple, subband e.g. AWG structures onto a single PIC. First high contrast test wafers have been manufactured and will be evaluated at the beginning of year 2. Next to AWG structures we will also investigate the use of microring and Mach-Zehnder interferometer structures as an alternative route for the wavelength selective component. A second major challenge is the interfacing between the single mode PIC and the multi-mode outside world. For this we work on multimode-to-single mode couplers, based on the so-called photonic lantern principle. Extensive fiber mode coupling simulations have resulted in a fiber bundle coupling geometry using 7 single mode fibers that will be connected to the PIC. Manufacturing of the MM-to-SM coupler devices is underway. The third challenge to cope with is the optical interfacing and packaging. Here we studied several manufacturing and assembling methods in order to couple the MM-to-SM coupler and the single mode fibers to the PIC.

Progress beyond the state of the art and expected potential impact (including the socio-economic impact and the wider societal implications of the project so far)

The technology being developed in InSPECT will ultimately have several societal and economical impacts. On the short term new broadband spectrometer modules like the microSpectrometer and solid state based light sources will become available that can be used e.g. in a healthcare setting for diagnostic purposes. Their compact size and cost effectiveness will allow for a more rapid introduction of new healthcare applications not only in the hospital, but also at the point-of-care setting. On the mid to long term, the realization of the nanoSpectrometer device allows for an ultimate size reduction, paving the way for spectral diagnostics in e.g. in-body implantable devices where size reduction is crucial.
Recently spectral sensing is also being introduced on the consumer market with low cost, handheld multiple-purpose (e.g. food-quality, drug quality and safety) devices, capable of measuring spectral fingerprints in the NIR spectral region (up to 1 micrometer). InSPECT technology allows to extend the spectral range of these sensing devices also beyond the 1 micrometer silicon cutoff wavelength, where additional important spectral fingerprints can be found and thereby increase the application spectrum.

Related information

Record Number: 186603 / Last updated on: 2016-07-14