rus
Issue #4/2021
V. M. Polyakov, A. S. Bobe, S. I. Tomashevich, D. S. Denk, D. N. Kaliteevsky, I. N. Kaliteevsky, A. L. Pavlova
Visible and Near Infrared Spectrometers for Scientific and Industrial Applications
Visible and Near Infrared Spectrometers for Scientific and Industrial Applications
DOI: 10.22184/1993-7296.FRos.2021.15.4.316.322
Spectrometers of the visible and near-IR ranges, designed for recording the spectral characteristics of samples of different nature, are presented. The device is based on the optical scheme of Czerny-Turner, rifled diffraction gratings are used. Spectrometers can be used as a separate module in spectrophotometers, spectrofluorometers, Raman spectrometers. The design of the device is based on high adaptation to specific tasks of industrial and scientific applications.
Spectrometers of the visible and near-IR ranges, designed for recording the spectral characteristics of samples of different nature, are presented. The device is based on the optical scheme of Czerny-Turner, rifled diffraction gratings are used. Spectrometers can be used as a separate module in spectrophotometers, spectrofluorometers, Raman spectrometers. The design of the device is based on high adaptation to specific tasks of industrial and scientific applications.
Теги: czerny-turner scheme raman spectrometers spectrofluorometers spectrometers of the visible and near infrared ranges spectrophotometers рамановские спектрометры спектрометры видимого и ближнего ик-диапазонов спектрофлюориметры спектрофотометры схема черни-тернера
Visible and Near Infrared Spectrometers for Scientific and Industrial Applications
V. M. Polyakov , A. S. Bobe , S. I. Tomashevich , D. S. Denk , D. N. Kaliteevsky , I. N. Kaliteevsky , A. L. Pavlova
OOO «GK R-AERO», St. Petersburg, Russia
OOO «Geofotonika», St. Petersburg, Russia
ITMO University, St. Petersburg, Russia
Spectrometers of the visible and near-IR ranges, designed for recording the spectral characteristics of samples of different nature, are presented. The device is based on the optical scheme of Czerny-Turner, rifled diffraction gratings are used. Spectrometers can be used as a separate module in spectrophotometers, spectrofluorometers, Raman spectrometers. The design of the device is based on high adaptation to specific tasks of industrial and scientific applications.
Keywords: spectrometers of the visible and near infrared ranges, Czerny-Turner scheme, spectrophotometers, spectrofluorometers, Raman spectrometers
Received on: 22.04.2021
Accepted on: 04.06.2021
The spectral study of light is a powerful tool that provides direct access to the study of the composition of substances, as well as the physical processes occurring in light sources. For example, a comparison of the spectral composition of the light transmitted through the sample under study with the spectral composition of the light before the sample makes it possible to directly study the molecular structure of the substance, which determines the central wavelengths and the absorption line strength [1]. The study of the radiation spectra of laser and LED sources offers the possibility to evaluate the quality of radiation. The study of Raman spectra allows us to turn to the atomic structure of matter [2].
The high literacy of the modern user of spectral equipment sets new requirements to the principles of creating new spectrometric products and their architecture. The modern user often generates tasks for challenging measurement designs, which do not exist on the market in the form of ready-made solutions. If you look at the Western market, you can see that the leading manufacturers offer a product line that consists of elementary blocks that can be used as an independent device, and of complex systems built using these elementary blocks[3,4]. At the same time, the elementary blocks are also available in OEM versions for integration into the customer’s systems.
The facts listed above determined the model for launching the spectral products of the R-AERO Group of Companies LLC, which is the line of diffraction spectrometers VISION2GO (Fig. 1). In terms of the spectral range, a universal optical design of the spectrometer and electronics for operating silicon and InGaAs receivers were developed. A feature of the optical arrangement is the operation of all elements on reflection and wide variability in the use of diffraction gratings with different mark frequencies. In combination with the in-house flexible software, this approach can be employed to solve a wide range of tasks as part of complex systems using standard mass-produced modules that gave a good account of themselves.
In particular, the main component around which the entire architecture of the product line is built is a compact spectrometer with a focal length of 50 mm, built according to the Czerny-Turner optical scheme using off-axis aspherical elements with astigmatism correction. To date, this scheme is used in the ranges of 200–1100 nm, 900–1600 nm and 900–2500 nm. The characteristics of the most mass-produced products are made available in the table. In the future, it is planned to expand the spectral range of the spectrometers up to 3–5 microns.
In the near IR range (Fig. 2), this scheme provides pixel sharpness with an entrance slit width of 50 µm (the entrance slit in the scheme is depicted with an increase of 1:1 to the receiver that has the pixel width of 50 µm).
In the visible range (Fig. 3) with the gap of 25 µm, the scheme facilitates achieving a confident resolution of no worse than 2 nm at the half-height of the peak in the range of 200–1100 nm.
By installing more dense gratings, the width of the available spectral range for the resolution can be exchanged. The information exchange protocol and software makes it possible to combine several elementary spectrometers into one and thus achieve a great informative value of measurements.
In addition to the spectrometers themselves, radiation sources are produced, such as stabilized halogen lamps and LED sources with PWM intensity control, as well as devices for introducing samples into the measuring circuit – flow cells, including those designed to withstand pressure up to 125 MPa and flow cells with a gap of up to 10 µm, condensers for reflectance measurement within the microscale and fiber probes.
The use of high-bit ADCs and low-noise power supplies make it possible to achieve a relatively low noise level (Fig. 4a and 5a) and a high dynamic range (Fig. 4b and 5b). In order to be synchronized with light sources and other processes, the spectrometers are equipped with a sync input. Activities are underway to improve hardware recording of the spectrum sequence to the internal memory of the spectrometer that is followed by transmission to the software via USB.
Software with built-in mathematical processing facilitates expanding the dynamic range additionally.
On the basis of the described modules, several complex devices were implemented that allow simultaneous recording of the transmission, reflection, and fluorescence spectra of liquid and solid samples. For example, a spectrophotometer (Fig. 7).
The spectrophotometer allows recording the transmission spectrum of liquid samples (Fig. 8) in the spectral range of 1600–1860 nm with optical densities up to 5, as well as recording the fluorescence spectrum of the sample when excited by radiation at a wavelength of 405 nm.
ABOUT AUTHORS
Polyakov Vadim Mikhailovich, vadim.polyakov@r-aero.com, R-AERO GC LLC, www.r-aero.com Technical Director, St. Petersburg, Russia.
Bobe Alexandra Sergeevna, Geophotonics LLC, optical engineer, ITMO University, Department of Applied and Computer Optics, St. Petersburg, Russia.
Tomashevich Stanislav Igorevich, Ph.D., Geophotonics LLC, software engineer, ITMO University; Associate Professor, Faculty of Control Systems and Robotics, St. Petersburg, Russia.
Denk Denis Sergeevich, R-AERO Group of Companies, electronic engineer, www.r-aero.com, St. Petersburg, Russia.
Kaliteevsky Dmitry Nikolaevich, LLC «GK R-AERO», design engineer, www.r-aero.com, St. Petersburg, Russia.Kaliteevsky Ilya Nikolaevich, R-AERO GC LLC, General Director, www.r-aero.com, St. Petersburg, Russia.
Pavlova Anna Leonidovna, R-AERO GC LLC, leading specialist in scientific and technical projects, www.r-aero.com, St. Petersburg, Russia.
Conflict of interest
The authors claim that they have no conflict of interest. All authors took part in writing the article and supplemented the manuscript in part of their work. JSC «LLS» is the official dealer of goods of LLC «GK R-AERO» on the territory of the Russian Federation and the CIS countries.
V. M. Polyakov , A. S. Bobe , S. I. Tomashevich , D. S. Denk , D. N. Kaliteevsky , I. N. Kaliteevsky , A. L. Pavlova
OOO «GK R-AERO», St. Petersburg, Russia
OOO «Geofotonika», St. Petersburg, Russia
ITMO University, St. Petersburg, Russia
Spectrometers of the visible and near-IR ranges, designed for recording the spectral characteristics of samples of different nature, are presented. The device is based on the optical scheme of Czerny-Turner, rifled diffraction gratings are used. Spectrometers can be used as a separate module in spectrophotometers, spectrofluorometers, Raman spectrometers. The design of the device is based on high adaptation to specific tasks of industrial and scientific applications.
Keywords: spectrometers of the visible and near infrared ranges, Czerny-Turner scheme, spectrophotometers, spectrofluorometers, Raman spectrometers
Received on: 22.04.2021
Accepted on: 04.06.2021
The spectral study of light is a powerful tool that provides direct access to the study of the composition of substances, as well as the physical processes occurring in light sources. For example, a comparison of the spectral composition of the light transmitted through the sample under study with the spectral composition of the light before the sample makes it possible to directly study the molecular structure of the substance, which determines the central wavelengths and the absorption line strength [1]. The study of the radiation spectra of laser and LED sources offers the possibility to evaluate the quality of radiation. The study of Raman spectra allows us to turn to the atomic structure of matter [2].
The high literacy of the modern user of spectral equipment sets new requirements to the principles of creating new spectrometric products and their architecture. The modern user often generates tasks for challenging measurement designs, which do not exist on the market in the form of ready-made solutions. If you look at the Western market, you can see that the leading manufacturers offer a product line that consists of elementary blocks that can be used as an independent device, and of complex systems built using these elementary blocks[3,4]. At the same time, the elementary blocks are also available in OEM versions for integration into the customer’s systems.
The facts listed above determined the model for launching the spectral products of the R-AERO Group of Companies LLC, which is the line of diffraction spectrometers VISION2GO (Fig. 1). In terms of the spectral range, a universal optical design of the spectrometer and electronics for operating silicon and InGaAs receivers were developed. A feature of the optical arrangement is the operation of all elements on reflection and wide variability in the use of diffraction gratings with different mark frequencies. In combination with the in-house flexible software, this approach can be employed to solve a wide range of tasks as part of complex systems using standard mass-produced modules that gave a good account of themselves.
In particular, the main component around which the entire architecture of the product line is built is a compact spectrometer with a focal length of 50 mm, built according to the Czerny-Turner optical scheme using off-axis aspherical elements with astigmatism correction. To date, this scheme is used in the ranges of 200–1100 nm, 900–1600 nm and 900–2500 nm. The characteristics of the most mass-produced products are made available in the table. In the future, it is planned to expand the spectral range of the spectrometers up to 3–5 microns.
In the near IR range (Fig. 2), this scheme provides pixel sharpness with an entrance slit width of 50 µm (the entrance slit in the scheme is depicted with an increase of 1:1 to the receiver that has the pixel width of 50 µm).
In the visible range (Fig. 3) with the gap of 25 µm, the scheme facilitates achieving a confident resolution of no worse than 2 nm at the half-height of the peak in the range of 200–1100 nm.
By installing more dense gratings, the width of the available spectral range for the resolution can be exchanged. The information exchange protocol and software makes it possible to combine several elementary spectrometers into one and thus achieve a great informative value of measurements.
In addition to the spectrometers themselves, radiation sources are produced, such as stabilized halogen lamps and LED sources with PWM intensity control, as well as devices for introducing samples into the measuring circuit – flow cells, including those designed to withstand pressure up to 125 MPa and flow cells with a gap of up to 10 µm, condensers for reflectance measurement within the microscale and fiber probes.
The use of high-bit ADCs and low-noise power supplies make it possible to achieve a relatively low noise level (Fig. 4a and 5a) and a high dynamic range (Fig. 4b and 5b). In order to be synchronized with light sources and other processes, the spectrometers are equipped with a sync input. Activities are underway to improve hardware recording of the spectrum sequence to the internal memory of the spectrometer that is followed by transmission to the software via USB.
Software with built-in mathematical processing facilitates expanding the dynamic range additionally.
On the basis of the described modules, several complex devices were implemented that allow simultaneous recording of the transmission, reflection, and fluorescence spectra of liquid and solid samples. For example, a spectrophotometer (Fig. 7).
The spectrophotometer allows recording the transmission spectrum of liquid samples (Fig. 8) in the spectral range of 1600–1860 nm with optical densities up to 5, as well as recording the fluorescence spectrum of the sample when excited by radiation at a wavelength of 405 nm.
ABOUT AUTHORS
Polyakov Vadim Mikhailovich, vadim.polyakov@r-aero.com, R-AERO GC LLC, www.r-aero.com Technical Director, St. Petersburg, Russia.
Bobe Alexandra Sergeevna, Geophotonics LLC, optical engineer, ITMO University, Department of Applied and Computer Optics, St. Petersburg, Russia.
Tomashevich Stanislav Igorevich, Ph.D., Geophotonics LLC, software engineer, ITMO University; Associate Professor, Faculty of Control Systems and Robotics, St. Petersburg, Russia.
Denk Denis Sergeevich, R-AERO Group of Companies, electronic engineer, www.r-aero.com, St. Petersburg, Russia.
Kaliteevsky Dmitry Nikolaevich, LLC «GK R-AERO», design engineer, www.r-aero.com, St. Petersburg, Russia.Kaliteevsky Ilya Nikolaevich, R-AERO GC LLC, General Director, www.r-aero.com, St. Petersburg, Russia.
Pavlova Anna Leonidovna, R-AERO GC LLC, leading specialist in scientific and technical projects, www.r-aero.com, St. Petersburg, Russia.
Conflict of interest
The authors claim that they have no conflict of interest. All authors took part in writing the article and supplemented the manuscript in part of their work. JSC «LLS» is the official dealer of goods of LLC «GK R-AERO» on the territory of the Russian Federation and the CIS countries.
Readers feedback
