Sheffield, UK, 16th June 2025: Phlux Technology, a manufacturer of avalanche photodiode (APD) infrared sensors, announces a 30 µm optical window version of the Aura family of 1550 nm Noiseless InGaAs® APDs.
The sensors, which are also available in 80 µm and 200 µm versions, are 12X more sensitive than traditional InGaAs APDs and have inherently fast impulse response and short diffusion tails. The new 30 µm version features lower capacitance at 0.15 to 0.4 pF, which increases the cut-off frequency to 3.5 GHz, compared to the 80 µm version at 1.8 GHz and 200 µm at 0.7 GHz. This makes it ideal for high-speed, time-critical applications, such as those found in gigabit speed optical communications, including free space applications, and optical time domain reflectometry (OTDR) test equipment.
The 30 µm Aura boasts an excess noise factor of <3.5 at a gain of 100 with low dark current and sensitivity 12X that of traditional APDs. Spectral noise current at a gain of 50 is 260pA/RtHz, which is 5.2fW/RtHz at R=1.0A/W. In addition, the damage threshold of 30 MW/cm², combined with fast recovery characteristics that minimize attenuation and event dead zones, delivers optimum performance in OTDR and fiber sensing applications. High optical dynamic range and the ability to operate across a wide range of pulse widths means that OTDRs can test longer or more lossy fibres.
The high sensitivity of Phlux APD sensors extends the range of infrared systems by up to 50% for a given laser power. Alternatively, they can enable substantial reductions in the laser power required, lowering system costs by up to 40% and size and weight by up to 30%. When laser power is reduced, thermal management is less challenging, and system reliability is enhanced. Aura APDs will operate at up to +85 °C with minimal performance degradation, which is significantly higher than traditional sensors. They are designed to meet MIL-STD-883, qualified to Telcordia GR-468 and are drop-in replacements for existing surface mount or TO-packaged components. The sensors will also be offered as bare die later this year.
Phlux CEO, Ben White, said, Were seeing growing demand for these high-speed, precision versions of our Aura Noiseless InGaAs APDs, particularly from the optical communications sector but in other areas such as optical test equipment and LiDAR. The expanded product family allows our customers to choose the optimum device characteristics for their application. Whichever product they select, theyre guaranteed industry-leading sensitivity and performance.
Noiseless InGaAs APD technology was developed by adding an antimony alloy to the compound semiconductor manufacturing process. The resulting devices operate with internal gain of up to 120, enabling the smallest signals to be detected above the noise floor.
The new sensors are sampling now, and datasheets can be downloaded here.
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These 30 µm Noiseless InGaAs® APDs are high-speed, high-precision infrared sensors
About Phlux Technology
Phlux Technology designs, manufactures and markets 1550 nm infrared (IR) sensors 12x more sensitive than alternatives. As a result, Phlux’s Noiseless InGaAs® Avalanche Photodiodes (APD) detect signals at up to 50% greater distance in range finders, LiDAR systems, and optical fibre test equipment. In every application, Phlux sensors boost performance, simplify thermal management, and cut system cost and size through relaxing laser and optics requirements. The sensors are available as bare die or in industry-standard surface-mount or wire-ended packages, so can be retrofitted to existing systems. The technology is cost-competitive for mass-market adoption.
Founded in 2020 and based in Sheffield, UK, Phlux Technology is a spin-out from the University of Sheffield. The company’s patented technology is the result of eight years of research at the university and its co-founders are Ben White (Phlux CEO), Jo Shien Ng (Professor of Semiconductor Devices), Chee Hing Tan (Professor of Opto-Electronic Sensors).
Phlux raised a seed funding round of £4 million led by Octopus Ventures in December 2022 and a £9 million Series A round led by BGF in March 2025.
More information about Phlux can be found at https://phluxtechnology.com
