Laboratory for the Study of Sensor Properties
Determination of the fluorescent and luminescent properties of solid, liquid and plastic samples in the 400–1100 nm spectral range. Analysis of photoemission characteristics for applications in optics, photonics, sensing and light-emitting devices. Study of photoinduced effects and evaluation of emitters, photonic components, and their quantum efficiency and photostability.
Description of Activities
Description of the Service
Determination of the Fluorescent/Luminescent Properties of Experimental Samples
Detailed description of the service: High-sensitivity optical spectral recording in the 400 – 1100 nm range, followed by analysis and determination of the photoemission characteristics of solid-state, plastic or liquid bulk samples, layers and structures used in optics, electro-optics, optomechatronics, sensing, photonics and biophotonics, as well as of various light-emitting and photonic devices. Detection and study of photoinduced, photostimulated and photocontrollable effects and processes in photosensitive and photoactive materials, and determination of their efficiency. Testing of photonic emitters, as well as of the devices in which they are incorporated.
On the basis of the experimental data, using appropriate mathematical models and analyses, the following can be determined: (1) the type and size of the photoemitting micro- or nanostructures in the material under study; (2) their distribution in the bulk or on the surface of the material under study, and their orientation (if any); (3) the photoinduced or photostimulated response time of the material under study (and of its individual components, if the material is a composite); (4) parameters of light-emitting and photonic devices, molecular photoswitches and optical sensor devices; (5) the functionality and efficiency (incl. quantum efficiency) of various photonic emitters and converters; (6) the photostability/photodegradation of optical materials/devices under continuous illumination – either integrally or in narrow spectral bands in different regions of the optical spectrum, within the 280 – 900 nm range.
Equipment
Equipment for the Study of Photocontrollable Sensors
Within the framework of the “Mechatronics and Clean Technologies” project, equipment for the study of photocontrollable sensors has been delivered to the Institute of Solid State Physics (ISSP-BAS). This infrastructure configuration comprises state-of-the-art, high-sensitivity electrical and spectrophotometric measuring instruments: (i) a high-frequency lock-in amplifier; (ii) a fast oscilloscope-digitiser; (iii) a high-sensitivity optical mini-spectrophotometer with a flexible optical fibre.
(i) High-frequency lock-in amplifier UHFLI (Zurich Instruments): a latest-generation combined phase-sensitive measuring instrument that also incorporates the functions of a dynamic signal analyser, a spectrum analyser, a digital pulse generator, a low-frequency function generator and a high-frequency generator. Its operating frequency range is from 0 to 600 MHz. It can operate in various measurement modes. The lock-in amplifier is integrated with a digital generator and features automated frequency variation – programmable sweeping with preset parameters (frequency range, frequency step and interval between measurements) for automating measurements, in linear or logarithmic mode, as selected. The instrument also offers programmable sweeping of the electrical phase offset.
https://www.zhinst.com/europe/en/products/uhfli-lock-in-amplifier
(ii) Portable fast oscilloscope-digitiser PicoScope 6407 (Pico Technology): a compact portable instrument that digitises, at very high speed, signals arriving via analogue channels (4 in total), while simultaneously displaying them. The operating frequency range of the instrument is suitably wide – 1 GHz – and the minimum time resolution in digitisation is 0.2 ns. External triggering is available. It has its own (built-in) signal generator (Arbitrary Waveform Generator, AWG).
https://www.picotech.com/oscilloscope/6407/picoscope-6407-features
(iii) Portable high-sensitivity optical mini-spectrophotometer with flexible optical fibre QE Pro-FL (OceanInsight): a modern multifunctional instrument. The optical spectral range of the instrument is 350 nm – 1100 nm. Photometric modes and measurement types: transmission, absorption, fluorescence, kinetic studies, and determination of reflectance and colour. The photodetector of the QE Pro-FL is a two-dimensional CCD array, thermoelectrically cooled, with a quantum efficiency of 90 %. The optical signal is fed into the instrument via a flexible quartz optical fibre with a diameter of 200 μm. The spectral resolution of the QE Pro-FL is up to 0.2 nm (FWHM), depending on the installed spectral slit. The instrument’s analogue-to-digital conversion is 18-bit, and its dynamic measurement range is 85000:1. The scanning speed over the entire operating spectral range is selectable, as are the options for spectrum accumulation.
Access to the Laboratory and Service Requests
The laboratory is part of the research infrastructure of the National Centre of Excellence “Mechatronics and Clean Technologies” and is located on the Geo Milev campus. Requests for access and for joint research are therefore handled centrally — see Contact. In addition, a full overview of the Centre’s other laboratories is available on the Infrastructure and Laboratories page.
The laboratory’s equipment was set up under project BG16RFPR002-1.014-0006, funded by the Research, Innovation and Digitalisation for Smart Transformation Programme 2021–2027, co-funded by the European Union through the European Regional Development Fund.