Christian Rookes is VP of marketing at Phlux Technology, a manufacturer of avalanche photodiode (APD) infrared sensors based in Sheffield, U.K. He has more than 25 years’ experience in technical marketing in semiconductor and optical communication fields. Rookes holds a BSc in Engineering and Physics from Loughborough University and an MBA Essentials Certificate from the London School of Economics. He holds two patents, including one related to impedance matching for laser diode circuits.

Compared to wireless systems, FSOC can operate with lower power consumption—which reduces cost and environmental impact. Narrow FSOC beams are also more focused than wireless emissions, and it boosts the received signal strength and mitigates the need for high-power transmitters. And antenna designs can be more compact using optics compared to RF. This reduces installation space constraints and aesthetic impact, which can be important where there is local sensitivity toward their presence. For cases in which the security of communications is important, FSOC systems may be preferred over wireless links because eavesdropping on optical links is technically challenging and the risk of interception is relatively low.

In medical applications, FSOC technology shows promise for communication with subcutaneous implants, where skin-induced propagation loss can be mitigated.

Farir

For Research Use Only. Not for use in diagnostic procedures. This page may contain references to products that are not available in your country. Please contact us to check the availability of these products in your country.

Digital camera sensors are made up of millions of tiny wells that collect photons of light. Each of these wells is called a photosite. During an exposure, each ...

Infrared spectroscopy

The future of FSOC looks promising and ongoing research and development is targeting enhancing system performance and expanding its applications.

Features: High quality professional optical glass lenses Works with eyepieceless stereo 3D microscope Specifications: Model: AJ5L04 Magnification: 4X ...

Measurements that are often conducted in the near-infrared region include the transmittance measurement of solutions. There are a variety of measurement samples that fall into this category, and aqueous solutions are one type. As is commonly known, the molecular extinction coefficient of water in the mid-infrared region is extremely large, and in most cases saturation occurs in absorption associated with the solvents. Therefore, there are many instances where the absorption associated with other substances cannot be confirmed. In contrast, when a 1 mm path length cell is used to conduct near-infrared transmittance measurement, in almost all regions, the absorption of substances present in the water can be confirmed (although this can be difficult at low concentrations). In addition, in the near-infrared region, as in the visible region, the absorption of glass and quartz is barely seen. Therefore, chemically stable and easy-to-handle glass and quartz can be used as materials for window plates and cells for measurement.

In 2024, a collaborative European initiative was launched to enhance Earth-to-FSOC technology. This project, supported by the European Space Agency (ESA), brought together a specialized sensor manufacturer, Phlux Technology, Airbus Defense and Space, and the University of Sheffield (U.K.). The primary objective of the ongoing work is to develop more efficient FSOC satellite terminals. The mid-range target is reliable 2.5-Gbit/s communication links operating at an IR wavelength of 1550 nm with low Earth orbit (LEO) satellites. The satellites typically orbit at altitudes up to 2,000 km above Earth's surface. Looking further ahead, the team aims to create systems capable of consistent 10-Gbit/s transmission rates. A radiation-hardened, integrated IR sensor and amplifier will be developed for the system.

infrared中文

Aug 23, 2011 — Why is 7mm so rare, though? As far as I can tell, sizes from 2mm through 10mm, including 2.5 and 5.5, are common, but nearly every set I've seen ...

What is a PC add-on card? An add-on card is a device that adds or enhances functionality, such as USB, eSATA, serial, parallel, ...

Atmospheric conditions have, until recently, been a limiting factor in distance and bandwidth capabilities in FSOC. But techniques to mitigate these, such as adaptive optics, are now used and result in improved data rates for a given bit error rate (BER).

1550 nm is a commonly preferred wavelength for FSOC. It is a sufficiently longer wavelength than visible light, so it’s “eye safe” if people encounter the signal, and avalanche photodiodes (APDs)—based on indium gallium arsenide (InGaAs) APDs—exhibit peak sensitivity to IR light at this wavelength. The Fraunhofer Heinrich Hertz Institute states that 1550-nm beams are 50x safer than those at 850 nm, which were also proposed for FSOC.

by VH Rumsey · 1951 · Cited by 82 — The description of elliptical polarization involves a statement about the relative amplitudes and phases of a pair of vibrating quantities, and this is also ...

FSOC operates on a straightforward principle: the transmission of modulated laser light through the air between a transmitter and receiver. This process involves lenses or parabolic mirrors to narrow and project the light toward the receiver where it is captured and focused onto an optical detector, typically a semiconductor photodiode. The optical signal is converted into an electrical one for processing (see Fig. 2).

A triangular prism has 5 faces, 9 edges, and 6 vertices. It is a polyhedron with 3 rectangular faces and 2 triangular faces. The two triangular bases are ...

In terrestrial applications, FSOC promises to be a cost-effective alternative to fiber-optic systems for high-speed connections in multipoint scenarios, such as large organizations or remote areas. Furthermore, its high capacity and low latency make it a promising technology for 5G backhaul links. Some hybrid systems are evolving that combine RF and FSOC technologies to provide greater reliability by adapting to varying weather conditions and interference levels.

infrared radiation中文

by KH Ulbrich · 1981 · Cited by 30 — Literatur · 1. M Barr -Autonomous Categories · 2. H Bass. Algebraic K-Theory · 3. A Fröhlich, C.T.C Wall. Graded monoidal categories · 4. G Garfinkel, M Orzech.

This positive forecast is despite the acknowledged challenges of environmental interference and installation capital costs. The report highlights the need for devices with greater photon efficiency to mitigate some factors that could limit growth.

Nov 13, 2024 — The meaning of MAGNIFY is extol, laud. How to use magnify in a sentence.

Ultraviolet-visible near-infrared (UV-Vis-NIR) spectrophotometers are also capable of measuring near-infrared spectra. However, the construction of UV-Vis-NIR spectrophotometers is different from that of FTIR spectrophotometers, and there are differences in data obtained by these two types of instruments. Following are examples of o-xylene transmittance measurement. The measurement results using the FTIR are shown in Figure 6, and the measurement results using the UV-Vis-NIR Spectrophotometer are shown in Figure 7. The horizontal axis shows the wavelength to facilitate comparison.

Fourier Transform Infrared spectrophotometers (FTIR) are mainly used to measure light absorption of so-called mid-infrared light, light in the wavenumber range of 4,000 to 400 cm-1 (wavelengths 2.5 to 25 µm), in order to identify and quantify various materials. By modifying the FTIR's interferometer beam splitter and detector to accommodate near-infrared light, FTIR spectrophotometers that can be used for near-infrared light measurement have been developed and commercialized. Measurement of near-infrared light is different in some ways from that of mid-infrared light, and some of the characteristics and considerations associated with near-infrared light absorption should be noted. Here we introduce some actual sample measurement examples to illustrate points that should be considered.

near-infraredwavelength

Most analysts predict strong growth for the FSOC market driven by growing demand for LTE networks, a desire for an alternative to RF technology, the requirement for more secure high-speed communications, and to address the challenges of last mile connectivity in optical networks—for fiber-to-the-premises (FTTP) and fiber-to-the-home (FTTH) installations.

As FSOC evolves, it is poised to play an increasingly significant role in various sectors—from space exploration to medical devices, and 5G networks to next-generation data centers. As advances in IR sensor technology leverage its unique advantages, FSO technology has the potential to revolutionize connectivity across diverse environments to meet the growing demand for high-speed, secure, and efficient communication systems.

The integration of FSOC technology with unmanned aerial vehicles (UAVs) could provide high-bandwidth communication in remote areas or during emergencies. For these applications, vertical-cavity surface-emitting lasers (VCSELs) may be preferred instead of APDs.

Up to here, we have spoken about the near-infrared transmittance measurement of liquids; however, the near-infrared transmittance method is also effective for measuring solids. Figure 4 shows a near-infrared transmittance spectrum of 1 mm thick polystyrene. It is clear that in near-infrared measurement, there is almost no saturation in the absorption of the 1 mm thick sample. A mid-infrared transmittance spectrum of a polystyrene sample having the same 1 mm thickness is shown in Figure 5. Here, the absorption saturation is evident. In measurement of solids, as shown here, samples of thickness that would be accompanied by absorption saturation in mid-infrared transmittance measurement can be measured without absorption saturation in the near-infrared region.

Infrared radiation

VynZ Research’s report “Global Free Space Optics Market – Analysis and Forecast (2025-2030)”, forecasts a 30% compound annual growth rate (CAGR) for FSOC between 2025 and 2030, with the global market, led by the U.S., to reach a value of $1.9B, up from just $550M in 2023.

The space sector has recognized the potential of FSOC technology, particularly for satellite communications. The technology can be used for both earth-to-satellite and satellite-to-satellite communication. In the latter scenario, its performance is particularly impressive because atmospheric factors do not impede performance and in space, data rates can scale into the terabit-per-second (Tbit/s) range. As a result, the reduced weight, lower power consumption, and higher data rates of FSOC make it a particularly attractive alternative to RF systems in these applications (see Fig. 3).

Mid infrared

One of the key technical challenges with achieving Earth-to-satellite and terrestrial FSOC is that the IR signals used to transmit data are diffracted as they pass through the troposphere, the atmospheric layer closest to Earth. Variations in our atmosphere's air temperature, humidity, and turbulence cause fluctuations in the intensity and angle of incidence of IR signals. This makes the beam wander over the signal detector area, which limits performance. The issue is addressed by using large-area receptors comprising multiple IR sensors.

Here we introduced characteristics and points to consider with respect to transmittance measurement in the near-infrared region. Next time, we will introduce methods of measurement other than the transmittance measurement method.

Infrared waves

The technology leverages the visible and infrared (IR) light spectrum, in contrast to the RF spectrum used by most wireless systems. This offers significant benefits, not least a vast unlicensed spectrum in which FSOC systems typically operate at near-infrared (NIR) wavelengths between 700 and 1600 nm.

Jan 2, 2024 — Hi there! If you're using the Spatial Filter option in the FeatureReader, it expects an initiator feature (or multiple features) with a geometry ...

These IR sensors are crucial components in FSOC receivers. Better sensors detect weaker signals, which enable development of faster, higher-bandwidth links with reduced latency. In Earth-to-satellite communications, they also improve performance because higher sensitivity allows maintenance of link integrity over a wider angle as the satellites pass overhead—resulting in longer periods of operation.

A further benefit of FSOC is that wireless channels are either regulated or where not regulated are already densely populated. FSOC needs no license and due to its narrow transmission angle, it is less susceptible to interference from other signals.

It is clearly seen that, as the temperature increases, the peak around 7,000 cm-1 shifts toward the higher wavenumber side. Table 1 shows the absorbance values with respect to temperature changes at 6,890 cm-1 (peak position at 25 °C). Table 1 Temperature and Absorbance of Water at 6,890 cm-1

As an example of aqueous solution measurement, Figure 2 shows the near-infrared spectrum of an ethanol aqueous solution. A cell with a path length of 1 mm was used. The absorption of water along with that of the dissolved ethanol was clearly confirmed. Thus, measurement of an aqueous solution, which is difficult in the mid-infrared region due to absorption saturation, is relatively easy in the near-infrared region.

Wireless communication has witnessed remarkable advancements in recent years, driven by a growing demand for higher data rates and capacity. As traditional radio frequency (RF) and microwave technologies struggle to keep pace with these growing requirements, free-space optical communication (FSOC) has emerged as a frontrunner, to address bandwidth limitations and last-mile connectivity challenges (see Fig. 1).

In measurement of this type of aqueous solution and samples with high water content, it is necessary to consider the factor of temperature. Figure 3 shows the spectra of water acquired at different temperatures between 25 and 80 °C.

The technology also shows great potential for intra-data-center communication, where its low latency and high bandwidth are attractive attributes.

Until recently, the sensitivity of 1550-nm APDs was limited by the internal noise generated within the devices, which limited the range and data rates achievable in FSOC systems. But in early 2024, noiseless InGaAs APDs were announced by Phlux Technology. These sensors, which add an antimony alloy to the compound semiconductor fabrication process, can detect exceptionally low levels of light down to single photons, which helps maintain signal integrity over long distances and under varying atmospheric conditions. They advance the performance of FSOC systems, offering 12x the sensitivity of traditional InGaAs APDs, which represents a potential 10.79-dB improvement in link efficacy before other noise sources such as amplifiers are considered (see Fig. 4).

Near-infrared light generally refers to light within the wavenumber range of 12,500 to 4,000 cm-1 (wavelengths from 800 to 2,500 nm) (see Fig. 1). Absorption of near-infrared light, like that of mid-infrared light, is based on the vibration of the material. However, near-infrared light absorption is much weaker in intensity as compared with mid-infrared light absorption, since near-infrared light absorption is based on overtones and combined tones in the mid-infrared light region. Therefore, measurement of samples showing weak absorption is difficult, but the fact that samples can be measured without being diluted is an advantageous feature. Furthermore, as solvents themselves show weak absorption, aqueous solutions are also relatively easy to measure. Various methods of near-infrared absorption measurement are known, such as the transmittance and diffuse reflectance methods, and these will be introduced using measurement examples.

Thus, it can be seen that as the temperature changes, the absorbance also changes in accordance with the wavenumber shift. For this reason, in near-infrared measurement of samples that contain water, absorbance around water absorption will fluctuate unless measurement is conducted at a constant temperature. The main cause of peak shift shown here is said to be temperature-induced changes in the hydrogen bond of the water molecules. Just to touch on the topic of the change in the hydrogen bond, in the near-infrared region, since there is a big difference in the peak positions of the hydrogen-bonded OH group and the non-hydrogen-bonded OH group, and since the peak intensity of the non-hydrogen-bonded OH group is relatively large, measurement is often conducted with respect to the hydrogen bond (Shimadzu Application News No. A365).

The first high-capacity space-to-ground laser communication system was installed on the Bartolomeo platform of the International Space Station (ISS) as part of a collaboration between Airbus Defense and Space, the Institute of Communications and Navigation of DLR (German Aerospace Center), and Tesat-Spacecom GmbH & Co. KG. The 2018 project, called OSIRIS, was designed to provide direct-to-earth (DTE) technology with a data rate of 10 Gbit/s over a range of about 1,500 km.

Shanghai Optics produces the highest quality plastic optics in a variety of shapes, including aspheric lenses, optical prisms, cylinder lenses, toroid lenses, ...

As can be confirmed from these figures, extremely high-resolution data can be obtained when measurement is conducted using the interferometer-equipped FTIR. The peak around wavelength 1.685 µm (5,950 cm-1) is separated into two. In contrast, the peak appears as a single peak in the case of the UV-Vis-NIR spectrophotometer, which uses dispersive elements. Although it depends on the instrument and measurement attachments, in transmittance measurement, a resolution of 8 to 16 cm-1 can be obtained using the typical settings with the FTIR, while it is about 50 cm-1 (5 nm by wavelength) around 10,000 cm-1 with the UV-Vis-NIR Spectrophotometer. On the other hand, the UV-Vis-NIR Spectrophotometer is generally acknowledged to provide better repeatability of absorbance values than the FTIR.

These advancements in APD technology are poised to significantly enhance the capabilities of satellite and terrestrial FSOC and potentially revolutionize space-based data transmission.