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Holiday break. The next issue of the Weekly Review will be published on September 9, 2024.
No. 26/2024 (June 24, 2024)
Will lithium niobate-coated glasses allow you to see in the dark?
Scientists affiliated with the Australian Research Council (ARC) have developed an infrared filter thinner than food wrap that will enable the wearer to view the infrared and visible light spectra simultaneously. For many years, scientists have been searching for lightweight and efficient materials that would enable the transformation of infrared radiation, invisible to humans, into visible light. Until recently, the main candidate was gallium arsenide. However, as it turned out, film made from lithium niobate and silicon dioxide lattices converts infrared light into visible light better than any other compound known to date, potentially enabling vision in the dark. After a series of experiments, the team has shown that the lithium niobate layer performs better, achieving 10 times more efficient conversion, and can convert high-resolution images from infrared light (with a wavelength of 1550 nanometres) to visible light (with a wavelength of 550 nanometres).
A device that can convert infrared light into visible light.
Traditional night vision technology requires infrared photons to pass through a lens and then hit a photocathode, which converts them into electrons. These electrons pass through a microchannel plate, which increases their number. They then pass through a phosphor screen, where they are again converted into photons, creating an enhanced image visible to the human eye. This system requires cryogenic cooling to prevent thermal noise amplification. A high-quality night vision system of this type, is heavy and bulky. In addition, it often has the disadvantage of blocking visible light.
Metasurface is a thin layer of material whose structure is designed at the nanoscale to control electromagnetic waves in a way that is not possible with traditional materials. Metasurfaces consist of a series of nanostructures, called meta-atoms, which can modify the properties of light, such as its phase, amplitude, polarisation or propagation direction. Due to their unique structure, metasurfaces can be used to create advanced optical devices such as variable focal length lenses, invisible cloaks or light frequency conversion devices. They are key in modern optical and photonic technologies, including the technology described here for converting photons from infrared to visible light.
Metasurface-based conversion technology needs far fewer components. Photons pass through a single resonant surface, where they are mixed with a pump beam (a stream of light or radiation that provides energy to help convert infrared photons into visible light photons). The resonant surface increases the energy of the photons and converts them into visible light, without the need for conversion to electrons. The technology operates at room temperatures, eliminating the need for large and heavy cooling systems.
Miniaturization of night vision technology could lead to its widespread use. The creation of night vision filters weighing less than a gram, which can be applied to traditional glasses in the form of a thin film, opens up new possibilities. Consumer night vision goggles that allow one to see both the visible and infrared spectrum at the same time could improve safety when driving at night, walking after dark or making it easier to work in low-light conditions. It is reasonable to believe that the military will quickly take advantage of this technology by equipping soldiers with glasses that allow them to see at night and in dark rooms.
Measurements of the attenuation of splices made with the Sendun SD-9+.
The Sendun SD-9+ L5877 fiber optic splicer is a model the production of which began in the second half of 2023. Despite its relatively short presence on the market, it has already managed to win a wide range of satisfied installers operating in various areas of FTTH networks and low-current systems using fiber optic cabling.Take a look at the video prepared by Dipol's team of engineers, presenting the Sendun SD-9+ splicer's capabilities in splicing single-mode optical fibers in G.652.D, G.657.A1 and G.657.A2 standards. Splice attenuation was verified in a two-way OTDR measurement made with a high-end EXFO brand OTDR.
The measurements showed that the splicer performs splices with good parameters, also when splicing fibers of different standards. When splicing G.652.D fibers, the average splice attenuation for 1310 nm was 0.06 dB, for the G.652.D – G.657.A1 splice it was 0.03 dB, while for the G.652.D – G.657.A2 splice it was 0.08 dB. During the 12 measurements, the worst recorded result was 0.12 dB, when combining fibers with extremely different mod field diameters. These results showed that the splicer can be successfully used in various installation scenarios.
In addition, the fiber image imaged by the 380x magnification optics and CMOS transducer allows accurate analysis of any anomalies occurring during splicing. This allows a preliminary assessment of the splice, right after it is made.
The video is intended for those interested in purchasing a fiber optic splicer, as well as those who already have a splicer. A high level of educational value of the video has been taken care of, so those interested in any of the issues:
- operating a fiber optic splicer
- preparing fibers for splicing
- splicing sheaths
- analyzing splices based on the image on the splicer's screen
- laying fibers in a coupler
- directional splicer attenuation measurements
are sure to find something of interest in it.
We cordially invite you to participate in the 23rd edition of the photo contest, organized by Dipol.
As every year, we look forward to your photos that will show antennas in a new light. These often inconspicuous structures made of steel, aluminum and plastic can be an inspiration for unique visual creations. We invite you to take a look at the works from previous-editions. They are sure to provide great inspiration for new and exploratory projects.
Your works will be judged by Pawel Zechenter, a well-known photographer and filmmaker from Krakow. We look forward to receiving your works by September 30, 2024.
Attractive prizes are provided for the winners and distinction winners:
1st place – DJI Osmo Mobile 6 Gimbal.
2nd and 3rd place: Wireless access pointTP-Link EAP650-outdoor.
Distinction winners will receive a mug from DIPOL's collection.
2nd and 3rd place: Wireless access pointTP-Link EAP650-outdoor.
Distinction winners will receive a mug from DIPOL's collection.
Building monitoring using ColorVu hybrid cameras from Hikvision's Easy IP 4.0 series.
The diagram below shows a monitoring system for a block of flats based on Hikvision IP DVR and ColorVu hybrid cameras that are part of the Easy IP 4.0 series. Smart Hybrid Light cameras from ColorVu combine the advantages of traditional cameras and ColorVu series cameras. The traditional cameras have an IR illuminator that illuminates the scene, allowing them to record images at night, at the expense of losing details in the form of colors. ColorVu cameras, can record color images around the clock, but the use of white light illumination is not always expected. Smart hybrid cameras with ColorVu technology, equipped with three modes of secen illumination: classic infrared, white LED light and smart mode. In smart mode, the camera triggers white light when it detects a human or vehicle silhouette, providing a color image. Once the object leaves the detection zone, the camera switches back to IR mode. In addition to illuminating the scene to provide a color image, the LED light has the additional function of deterring an intruder. What mode the camera will operate in is decided by the user. The facility described here was secured from the outside with 8 compact housing cameras DS-2CD2047G2H-LIU K03212 with 4 MP resolution, equipped with a 2.8 mm fixed focal length lens and 89.2° viewing angle. Inside the building, there are four dome cameras Turret DS-2CD2347G2H-LIU K01304 with 4 MP resolution, equipped with 2.8 mm lenses with 111° viewing angle. The cameras have a white light and IR illuminator with a range of up to 40m.Surveillance of a block of flats using Hikvision cameras from the EasyIP 4.0 series
The proposed deployment of cameras allows accurate identification of people. The cameras are powered and connected to the NVR via the N29986 16-port PoE switch. The cameras support H265+, H.265, H.264+ and H.264 codecs. With the use of two 4 TB hard drives, e.g. M89305, H.265 video compression and continuous recording mode at 25 fps for each camera, the data retention time is 14 days.
Simulation of archiving time of recordings using Storage and Network Calculator program
What is it worth using CCTV tester network tools for?
The Alpsat AS33-IPCX M3214 meter is not only a tool that allows you to easily view camera images. It is also worth noting the integrated network applications that can assist and simplify the system process. These include:- IP network scanner
- port scanner, sending ICMP packets (ping)
- IP tools – showing the occupancy of IP addresses in a subnet
- DHCP server
- NET-port blinking – detecting a connected port in a switch
- network analysis (connection speed, packet loss, loop detection)
- continuous communication test with IP addresses, Traceroute – packet route testing
- network bandwidth test
- network calculator
- network search for devices from a specific manufacturer
For example, when adding a new IP camera or other device to the network, it is important not to assign it an already occupied IP address, because then there would be an address conflict and the equipment would stop working properly. The IP address scanner function allows you to check if the IP address you want to assign is not already in use. You can test a selected network segment to make sure that the IP address you want to assign to devices is free. The status of an IP address is indicated in green when it is free, or in red when the IP address is busy.
A snapshot of how the free IP address scanning function works
On the other hand, in case you have a large system and you do not know which port on the switch your cables are connected to, you can use the port busy detection function on the switch. The device can send a signal that makes the LED of a specific port blink at a set frequency (normal speed – every 2 seconds, slow speed – every 4 seconds). With this feature, it is easy to find the other end of the cable. The cable under test should be connected to the LAN port of the tester and the network tools should be turned on, and in them the port detection function of the switch.
A snapshot of the operation of the Port Detection function in the switch.
COMBO-type meters for TV signal measurement.
The RF Level expressed in dBμV is not the only parameter to consider when measuring digital terrestrial DVB-T2 as well as DVB-S/S2 satellite TV. Equally important, if not more important, are Modulation Error Ratio (MER) and Link Margin. MER can be treated not as an indicator of the signal quality, but as a measure of the distance of the received signal to the digital cliff. Without knowing this parameter, the antenna installer cannot guarantee stable reception in adverse weather conditions or other situations when the signal can fluctuate (e.g. interfered by a passing truck). Providing a margin of safety (a sufficiently large distance from the cliff) by measuring the MER, will avoid this type of situation. Typical and minimum values of the MER parameter for proper reception depend on modulation technique. For 256-QAM modulation, 28.5 dB should be taken as the minimum value, while typical values are 31.5 dB and above.Link Margin is a measure that indicates the margin of safety (a sufficiently large cliff gap) by measuring the MER. When Link Margin is at or near zero, the decoder is unable to recover lost data, resulting in a loss of signal. A high Link Margin is important because it ensures signal tolerance to degrading factors such as interference or system aging. When measuring terrestrial or satellite TV, pay attention not only to MER, but also to Link Margin. The boundary between an ideal signal and its complete absence is very narrow. Therefore, even in the case of slight signal degradation, you can see image artifacts and freezes on the TV screen. The higher its value, the greater the tolerance of the signal to degrading elements. A properly set amplifier, high-quality cabling, a minimum number of intermediate connections and other good practices will ensure Link Margin, which will protect the system from future signal loss.
Comparison of key features of COMBO-type meters for DVB-T2 digital terrestrial and DVB-S/S2 satellite measurements:
 |  |  | |
| Code | R10206 | R10210 | R10155 |
| Calibration certificate | YES | NO | NO |
| Spectrum analyzer | YES | YES | NO |
| Real-time signal spectrum analyzer for detecting interference from mobile signals | 5G, LTE 4G, GSM, DCS, UMTS 3G | NO | NO |
| Measuring parameters | Link Margin, RF Level, MER, bBER, aBER | RF Level, MER, aBER | RF Level, MER, aBER |
| Export measurements to .csv file | YES | NO | NO |
| Firmware upgrade | Automatically via RJ-45 port | File | File |
| RF – signal strength | 25...100 dBμV | 30...90 dBμV | 44...85 dBμV |
| Battery – capacity | 7000 mAh | 5000 mAh | 2600 mAh |
An ideal place to terminate cabling – RACK cabinets.
Aesthetically pleasing and functional RACK cabinets are designed for mounting devices with enclosures designed in 19" (482.6 mm) standard. The 1.75 inch (44.45 mm) "U" unit standardizes the height of devices in RACK cabinets. The capacity of cabinets is related to their height and is determined by the "U" units. Another important parameter is its depth (outer dimension), which is specified in millimeters, for example 450, 600, 800 mm. This parameter is important for e.g. computers or data loggers due to the fact that their depth varies. You should check if a particular device will fit into a given enclosure, and if there is enough space for cables.RACK cabinets are ideal for the system of patch panels, switches, computers and optical devices. In the cabinet, using the shelves, you can also place non-RACK-19" devices, such as multiswitches, RF/SAT amplifiers, modulators, recorders, etc.
When selecting a RACK cabinet, of course, the number of panels should be provided for proper cable termination. However, this is not all. In addition to the height of the cabinet itself, it is worth thinking about:
- an adequate amount of space for mounting active devices; in the case of a typical multi-family building, this will be the set of amplifiers and multiswitches shown in the picture, performing RF/SAT signal distribution. Adequate width and depth of the cabinet will allow to mount the above devices on the side or rear. This saves valuable space on the front.
- vertical cable organizers – since the number of cables that enter the cabinet is large, the number of cables that cross the operator's devices (LAN switch optical splitter, etc.) with termination panels will also be large. Therefore, choosing a cabinet model equipped with vertical cable organizers seems to be the only right one. Without this element, sooner or later, there will be a huge mess on the front of the cabinet.
- the possibility of convenient and safe introduction of cables from external operators - vertical cable organizers can also be used by external operators to safely and as conveniently as possible introduce their own cabling into the cabinet. Here we are talking about multipatchcords, cables feeding optical splitters, etc. If this issue is not carefully considered, and operators are left with a free hand in this regard, they will end up with a mess, which in turn will affect the possibility of failures.
The following photos show an example of the implementation of wiring completion in a multi-family building with 102 apartments. According to the current regulations, the cabinet located in the technical room is to be the point of convergence of cables from all apartments. Each apartment should be provided with 2 coaxial cables, 2 twisted-pair computer cables and 1 dual-fiber optic cable.
 |  |
SIGNAL RACK cabinet R912016 meeting the above requirements used to terminate the cabling in a multi-family building.
A Terra multiswitch system mounted on the back of the cabinet.
A Terra multiswitch system mounted on the back of the cabinet.
 | NETSET U/UTP cable cat. 6A B2ca s1a,d1,a1 /500m/ E1618_500 is a high-quality cable designed for professional systems for indoor fire escape routes. The shielding layer made of aluminum foil minimizes crosstalk and interference with the external environment. Enhanced flammability class – CPR classification: B2ca s1a,d1,a1. | |
 | Single-mode patchcord PC-1272D-5 2xSC/UPC – 2xSC/APC, duplex, G.657.A2, 5m L3221272_5 is a 5 m long section of single-mode fiber optic cable terminated with SC/UPC and SC/APC connectors. The patchcord is manufactured based on single-mode fiber in the G.657.A2 standard. This standard is characterized by a reduced bending radius. As a result, the patchcord is much less vulnerable to damage and increased attenuation caused by excessive bending. This is especially important when connecting fiber optic cables in small boxes, boxes or cabinets (e.g., the common case of crushing patchcords connected to fiber optic front panels with doors). | |
 | The PSC12015 power supply (12 V, 1.5 A, flush mount, IP67) M5716B is designed to supply 230 VAC to cameras in a CCTV system requiring 12 VDC. The power supply is equipped with short circuit, overload and overvoltage protection. Compact, sealed housing (IP67) allows installation in electrical boxes, housings and camera mounts. | |
Worth reading
HDMI-DVB-T/C digital modulator for single-family houses. The conversion of A/V signals into high-frequency RF signals, meaning the introduction of signals from all kinds of signal sources, such as computers, players or surveillance cameras, into a terrestrial TV system, is an operation that requires the use of a so-called modulator. Such device has an HDMI input and an RF output (commonly known as the "antenna output”), and it allows you to watch the video and listen to the sound on the selected channel, on all TVs connected to the system. For the receiver, the program added to the system is just another terrestrial television channel...>>>more
Distribution of HD quality signal from any HDMI source and terrestrial DVB-T2 TV in coaxial cable with example application of Signal R86301 modulator.
Sunell cameras – advanced features at an affordable price
