Modern science is actively developing in various directions, trying to cover all possible potentially useful areas of activity. Among all this, optoelectronic devices should be singled out, which are used both in the process of data transmission and their storage or processing. They are used almost everywhere where a more or less complex technique is used.
What is this?
Optoelectronic devices, also known as optocouplers, are special semiconductor-type devices capable of sending and receiving radiation. These structural elements are called photodetector and light emitter. They may have different options for communication with each other. The principle of operation of such products is based on the conversion of electricity into light, as well as the reverse of this reaction. As a result, one device can send a certain signal, while the other receives it and "decrypts". Optoelectronic devices are used in:
- equipment communication units;
- input circuits of measuring devices;
- high voltage and high current circuits;
- powerful thyristors and triacs;
- relay devices and sonext.
All such products can be classified into several basic groups, depending on their individual components, design or other factors. More on that below.
Emitter
Optoelectronic devices and devices are equipped with signal transmission systems. They are called emitters and, depending on the type, the products are divided as follows:
- Laser and LEDs. Such elements are among the most versatile. They are characterized by high efficiency, a very narrow beam spectrum (this parameter is also known as quasi-chromaticity), a fairly wide range of operation, maintaining a clear direction of radiation and very high speed. Devices with such emitters work for a very long time and are extremely reliable, they are small in size and perform well in the field of microelectronic models.
- Electroluminescent cells. Such a design element shows a not very high conversion quality parameter and does not work for too long. At the same time, devices are very difficult to manage. However, they are best suited for photoresistors and can be used to create multi-element, multi-functional structures. Nevertheless, due to their shortcomings, now emitters of this type are used quite rarely, only when they really cannot be dispensed with.
- Neon lamps. The light output of these models is relatively low, and they also do not withstand damage well and do not last long. Differ in large sizes. They are used extremely rarely, in certain types of devices.
- Incandescent lamps. Such emitters are used only in resistor equipment and nowhere else.
As a result, LED and laser models are optimally suited for almost all areas of activity, and only in some areas where it is impossible to do otherwise, other options are used.
Photodetector
Classification of optoelectronic devices is also made according to the type of this part of the design. Different types of products can be used as the receiving element.
- Photothyristors, transistors and diodes. All of them belong to universal devices capable of working with an open type transition. Most often, the design is based on silicon, and because of this, products get a fairly wide range of sensitivity.
- Photoresistors. This is the only alternative that has the main advantage of changing properties in a very complex way. This helps to implement all sorts of mathematical models. Unfortunately, it is photoresistors that are inertial, which significantly narrows the scope of their application.
Beam reception is one of the most basic elements of any such device. Only after it can be received, further processing begins, and it will not be possible if the communication quality is not high enough. As a result, great attention is paid to the design of the photodetector.
Optical channel
The design features of products can be well shown by the used designation system for photoelectronic and optoelectronic devices. This also applies to the data transmission channel. There are three main options:
- Elongated channel. The photodetector in such a model is far enough away from the optical channel, forming a special light guide. It is this design option that is actively used in computer networks for active data transmission.
- Closed channel. This type of construction uses special protection. It perfectly protects the channel from external influences. Models for a galvanic isolation system are applied. This is a fairly new and promising technology, which is now being continuously improved and gradually replacing electromagnetic relays.
- Open channel. This design implies the presence of an air gap between the photodetector and the emitter. Models are used in diagnostic systems or various sensors.
Spectral range
In terms of this indicator, all types of optoelectronic devices can be divided into two types:
- Near range. The wavelength in this case ranges from 0.8-1.2 microns. Most often, such a system is used in devices using an open channel.
- Long range. Here the wavelength is already 0.4-0.75 microns. Used in most types of other products of this type.
Design
According to this indicator, optoelectronic devices are divided into three groups:
- Special. This includes devices equipped with multiple emitters and photodetectors, sensors for presence, position, smoke, and so on.
- Integral. In such models, special logic circuits, comparators, amplifiers and other devices are additionally used. Among other things, their outputs and inputs are galvanically isolated.
- Elementary. This is the simplest version of products in which the receiver and emitter are present in only one copy. They can be both thyristor and transistor, diode, resistive, and in general, any other.
All three groups or each separately can be used in devices. Structural elements play a significant role and directly affect the functionality of the product. At the same time, complex equipment can also use the simplest, elementary varieties, if it is appropriate. But the opposite is also true.
Optoelectronic devices and their applications
From the point of view of the use of devices, all of them can be divided into 4 categories:
- Integrated circuits. Used in a variety of devices. The principle is used between different structural elements using separate parts that are isolated from each other. This prevents the components from interacting in any way other thanthe one provided by the developer.
- Insulation. In this case, special optical resistor pairs are used, their diode, thyristor or transistor varieties, and so on.
- Transformation. This is one of the most common use cases. In it, the current is transformed into light and applied in this way. A simple example is all kinds of lamps.
- Reverse transformation. This is a completely opposite version, in which it is light that is transformed into current. Used to create all kinds of receivers.
In fact, it's hard to imagine almost any device that runs on electricity and lacks some form of optoelectronic components. They may be presented in small numbers, but they will still be present.
Results
All optoelectronic devices, thyristors, diodes, semiconductor devices are structural elements of different types of equipment. They allow a person to receive light, transmit information, process or even store it.
