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ITMO University laboratories: LED lighting, microwave optoelectronics and optical telecommunications

We show the laboratory of LED lighting . We tell how it is arranged and what students do in it, as well as give an overview of stationary and mobile equipment.

By the way, we have already adapted some of our reviews for the English version of Habr:


In the final part of the review, we give a brief story about another location and related equipment - the laboratory of microwave optoelectronics and optical telecommunications .


In the photo: Sergey Aleksandrovich Scheglov, Head of the Laboratory

Research part


The laboratory focuses on scientific projects related to the high-speed transmission of visible light data, the study of the properties and characterization of semiconductor emitting devices, the modeling of emitting systems and their verification.

Students from the undergraduate program " Laser Photonics and Optoelectronics " and the master's program " LED Technologies and Optoelectronics " are studying here .

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The laboratory is divided into two parts: educational and research. In the first, students carry out laboratory work. In the second, research and research are being conducted on more sophisticated equipment. They are performed by the most scientifically active students and graduate students.

Part of the work of large scientific projects is also carried out here.

In general, the premises of the research laboratory are designed for three to four workplaces - with computers and stands for measuring and assembling optical circuits.

As for the equipment, that is, both stationary installations that cannot be carried, and mobile devices - we will show them a little later. The photo below shows the Flux goniophotometer.


In the photo: Flax goniophotometer

This is a tool for monitoring the spatial radiation of the lighting characteristics of both small LEDs and street lights. The goniophotometer is located in a special dark room, which is a collapsible design. The room allows you to measure the properties of optical and lighting systems without extraneous "flare."

The goniophotometer includes a goniometer , a device for high-precision measurement of angles, as well as a photodetector that records light intensity readings. The system works as follows:

  • the LED is connected to the power supply and its spatial distribution of the light intensity, which forms the so-called photometric body, is measured;
  • the photodetector is connected to a controller that transmits data to a laptop with special software (the software registers a signal when the angular position changes);
  • On the basis of the obtained data, a 3D model of the light source is compiled for the lighting engineering calculation of the premises, for example, in the special DIALux program.

Mobile lab


The laboratory has portable instruments with which employees can take measurements “in the field”: to explore the light environment of rooms and urban spaces.

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The device that Sergey mentions is shown in the photographs below. It allows you to evaluate various spectral characteristics: chromaticity coordinates, color quality, transmittance. A special mobile application is provided for the gadget.


In the photo: UPRtek MK350S compact spectrometer.


In the photo: UPRtek MK350S compact spectrometer. The

portable spectrometer is stored in a special case. At one time, students drew parallels with the “Revisionorro” program - there, the presenter also takes out a case and put on seals before checking. Another device that has its own suitcase is a bright meter. It is somewhat reminiscent of a manual radar used by traffic police. As the name of the device implies, it is necessary for measuring brightness (“blinds / does not blind”).

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In the photo: LS-110 brightness meter.

To work on the Lensvet project, the laboratory also acquired a German TechnoTeam device. At first glance, this is just a Canon camera, but in fact - a system for assessing the distribution of brightness. It is calibrated and has its own serial number.

The device digitizes the photo by brightness and generates an array of data for processing. They removed the sidewalk and roadway to determine if there are any objects in the driver’s field of vision that blind, interfere with driving. This approach significantly accelerated the workflow - with a conventional brightness meter, more than one hundred measurements would have to be made, since it has a very small central measurement zone.


In the photo: LS-110 bright meter

Another portable laboratory instrument is a power meter. With it, you can evaluate the electrical parameters of light sources: current voltage, current, power factor, apparent power, mains frequency and operating time.


In the photo: electric power meter.

Another small instrument in the arsenal of the laboratory is a thermal imaging camera connected to a computer. It shows the temperature distribution for luminaires or other semiconductor sources: where they are heated very much, and where - weakly.

“Suppose we lit a lamp, measured its electrical parameters. It warms up long enough for an hour, only after that you can make a measurement. And here we look, where he has the hottest point, what are his critical temperatures, ”says Sergey.


In the photo: a spectrometer with an integrated measuring sphere


In the photo: a spectrometer with an integrated measuring sphere

There is another interesting tool - a spectrometer with an integrated measuring sphere. It allows you to evaluate the characteristics of LED directly in the luminaire or LED module, without soldering semiconductor devices. It is also convenient during experiments.

If you did the calculation, you had to get one common light flux from the module, but got another, then with the help of a spectrometer you can check individual LEDs and understand what went wrong. Either they put the wrong LEDs, or they do not work that way.

Training lab


The training laboratory has an interesting set of light filters. Students measure the transmittance, and then try to make some color by adding two or three glasses. This is such a creative work to get different shades.


In the photo: light filters

In the photo below - a goniometer. Students examine the passage of visible radiation from a lamp through a narrow slit and a triangular prism. After setting up the instrument, they will receive a line spectrum and decomposition from blue to red.


In the photo: goniometer, device for angular measurements.

All devices are simple and reliable - it is rather difficult to break or ruin them.



Further on the photo there is a complex based on an integrating sphere with a special white coating. The scope is needed to evaluate the parameters of small lamps and LEDs that can be placed inside. On the goniometer, this process takes a long time, but here it is instantaneous: they turned it on, took measurements, and got the result.



For students, we have introduced the discipline of design activity. Within its framework, they must develop some kind of end device, device or installation, having gone through all the stages: from the formation of the development task to its implementation.



The guys are creative - for example, one student made a lightsaber (pictured above). He makes sounds, plays the Imperial March, and blinks in contact with other objects. Another project is a traffic light. Typically, LEDs have their own wiring to a certain control element. But students found an interesting LED strip in which each LED has its own controller, and connected it to the Arduino board. The signal passes from one LED to another and turns them on, depending on the prescribed logic.

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The laboratory studies the interaction of optical radiation and microwave signals in the conditions of reception, transmission and processing of information. Three undergraduates and seven graduate students work here, but sometimes new guys come, including bachelors. They all conduct experiments related to their research - some using lasers, some using photodetectors, some using LEDs.


Within the walls of the laboratory, inter-institutional projects are also being implemented. We work with colleagues from Fiztekh and Polytechnic, as well as with the enterprises of the OKB "Planet" and "Connector Optics". This is an important aspect for the development of science: we help research them, and they - to us.


In the photo: on the left is the probe station, on the right is the vector network analyzer.

As for the laboratory equipment, there are instruments that allow measuring the parameters of crystals of lasers and photodetectors operating in the frequency range up to 40 GHz.

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In the photo: vector network analyzer

Next to the probe station is a vector network analyzer, which is a generator and receiver of a high-frequency signal. The instrument measures the amplitude-frequency response of passive microwave devices or optoelectronic devices. The analyzer shows the response to a signal with an arbitrary amplitude at any frequency from the measuring range.


In the photo: optical spectrum analyzer

“There is also an optical spectrum analyzer. A unique device with a resolution of less than a picometer. The most accurate device in Russia. By the way, the second most accurate device is also with us. One is designed for the range of 1500–1600 nm, and the second - for the range of 1300 nm. They are used by modern telecommunication systems, ”Olga Andreevna explains.

There is also an impedance meter in the laboratory. It is used to study such characteristics of devices and passive components as resistance, capacitance and inductance. Measures to the nearest hundredths of picofarads and microohms.

We have a system for measuring current-voltage characteristics. It does not have an interface and connects to a computer. But by placing the crystal on the probe station and connecting to the corresponding terminals, we can remove the static characteristics of semiconductor devices, that is, the dependence of current on voltage. On their basis, the operating mode and maximum permissible values ​​of currents and voltages are already determined.

LED lighting


The laboratories are developing in the field of the so-called Li-Fi - a system that transmits data using light (almost like Morse code). A device is connected to the lamp, which makes it blink with a very high frequency, invisible to the eye. This flicker encode the necessary information. One of the implementation options is the so-called 2D-code (two-dimensional barcode), which can be considered a smartphone camera.

Museums can become a potential technology application. Above each picture, you can hang a lamp that will simultaneously illuminate a work of art and broadcast a 2D code. It is enough for the visitor to open a special application that recognizes the signal and redirects to the resource with additional information about the picture. Implemented a similar projectPanasonic at the State Museum of Fine Arts. A.S. Pushkin.

Another case is navigation. Lamps will be able to transmit the exact coordinates in a room, for example, a shopping center, and mark a place on the map.



Similar work is carried out within the framework of practice-oriented R&D - these are complex studies related to programming and signal processing. In partnership with O2 Lighting Systems, ITMO University experts presented prototypes of the client and host modules for working in the Li-Fi network. They plan to use the technology in areas where Wi-Fi is powerless - in airplanes or on underwater objects.


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