Avalanche Photodiodes (APDs)
Si-APD are suitable for the spectral range from 255 nm to 1100 nm.
The SAE series features an epitaxial structure and is available as red enhanced (i.e. optimized for visible wavelengths) or NIR enhanced (i.e. optimized for NIR wavelengths) version. These APDs are inexpensive and feature a very large gain and dynamic range.
The SAR series is based on a reach-through structure with a high sensitivity across the entire spectral range from 400 nm to 1100 nm. At the same time, rise and fall times are extremely fast (typically 450 ps). These APDs feature extremely low noise low dark current.In this series, lightpipe versions are available that have an optical fiber integrated into the cap; this fiber guides the light directly to the chip.
Specifically selected APDs (SARP series) can also be used for photon counting in Geiger mode (VR > VBR), where a single photon triggers an avalanche impulse of approximately 108 charge carriers. This APD is particularly suited for spectroscopy, fluorescence measurement, medical technology, and high end LIDAR applications.
One of the most common applications of Si-APDs is rangefinding systems based on the time-of-flight method (LIDAR). In the time-of-flight method, a 905 nm pulsed laser diode emits a laser pulse that reflects off an object and is focussed through an optic onto an APD chip. In order to achieve an optimal signal-to-noise ratio, an external band-pass filter that blocks the surrounding light has to be mounted in front of the APD or the optic. In the new SARF series, this filter comes already integrated into the TO housing.
Low cost APDs in a miniature SMD packages. Responsitivity is optimized for 850 nm and 905 nm rangefinders. Optional, the SAHA series is also available with 905 nm bandpass filter.
Silicon APD for Photon Counting
The SAP-series silicon avalanche photodiodes are primarily used in photon counting. This series features highest efficiency and lowest dark current rates.
The SAP500 series is based on a “reach through” structure with excellent quantum efficiency as well as extremely low noise and dark current. This APD, which has an active area of D=500 µm, can either be operated in normal linear mode (VR < VBR) with an internal gain of 250 or more or in “Geiger” mode.
Silicon APD UV sensitive
The detector was developed specifically for (bio)medical applications in which the smallest signals in the short-wave UV/blue spectral range have to be detected.
The SUR-Series is based on a silicon “reach-through” structure with high sensitivity in the DUV/UV wavelength range. The benefit of the SUR-Series is an extremely high sensitivity and low noise performance operating in the blue wavelength range and superior to any similar detector available presently on the market.
An important additional advantage of the new reach-through APD is its unmatched noise and sensitivity performance over the widest commercially available wavelength range, from 255 nm to 1000 nm.
These InGaAs avalanche photodiodes detect in the spectral range from 1100 nm to 1700 nm. IAG series APDs exhibit particularly high damage threshold values. Both come packaged in a TO-46 housing.
InGaAs-APDs are suitable for the spectral range from 1100 nm to 1700 nm. Compared to germanium APDs, they feature a significantly improved noise ratio, a higher bandwidth in relation to the active area, and advantages resulting from the increased sensitivity of up to 1700 nm.
All APDs in a TO-46 housing are available fiber coupled on an optional basis.
The IAG series exhibits a high damage threshold of >200 kW/cm². The responsivity of the detector peaks at 1550 nm and the active area is available in diameters of 80 µm, 200 µm, and 350 µm.
Silicon APD Arrays
APD-arrays are now available from Laser Components, enabling new applications in LIDAR and ACC.
Typically used in Time-of-Flight (TOF) sensors for distance measurement, for example in automotive safety sensing applications, linear APD arrays are now available from Laser Components.
Combining low-noise, high-sensitivity silicon avalanche photodiodes in a monolithic assembly, the arrays have been optimized for the 800-900 nm wavelength range. Further features include a low temperature coefficient and a gap of only 40 µm between elements. The arrays can be configured to fit the customer’s requirement in terms of the number and size of the array elements. 8-, 12- or 16-element arrays in a 14-pin DIL package are also available as standard (datasheets available). 2D matrix arrays are currently under development.
APDs with matched, integrated pre-amplifier in compact hermetic packages.
The performance of an APD in a specific application is often limited by the pre-amplifier, therefore the pre-amplifier needs to be chosen and implemented with great care in order to achieve the best possible signal-to-noise ratio. Our H-series receivers offer the user an APD with matched, integrated pre-amplifier in a compact, hermetic package.
All the receivers listed below are available with silicon* or InGaAs**-APDs and are therefore suitable for the wavelength ranges 400 – 1100 nm and 1000 – 1650 nm respectively.
* (SAE-, SAR-, SAT-Series)
Fast and reliable detection of light. In APD modules the driver for operating the avalanche photodiodes is already included.
APD modules enable very low light levels to be detected quickly and simply in a variety of applications such as laser radar, rangefinding, data transfer or biomedical analysis.
The APD modules are based on low-noise avalanche photodiodes made of either silicon or InGaAs with a built-in pre-amplifier and high voltage supply. A temperature compensation function allows the APD to be operated at constant gain across a wide operating temperature range.
High Voltage Modules for APD
Miniature high-voltage modules are particularly suitable for APDs and PIN photodiodes! The digital bias controller (dBC) series has three modules and achieves – even at dimensions of just 21 x 21 x 10 mm – an output power of up to 380 V!
In addition, with dimensions of only 40 x 40 x 13 mm the modules can be easily integrated into circuit boards. The modules contain a pulse generator working at a clock frequency of about 100 kHz and output ripples are only 25 mVss. The output voltage follows the input control voltage with a tolerance of 0.1%. The control voltage can be created externally or internally by connecting a potentiometer to the internal 5 V reference voltage. The input is surge protected.
Upon exceeding the maximum output voltage by a few percentages, the modules switch to a harmless constant current mode. Test outputs for output voltage and output current make monitoring easy.
Two types of high voltage modules are available with different output voltages and currents: the HV1500-41 for 50 to 1500 V/1 mA and the HV3000-42 for 100 to 3000 V/0.4 mA. The modules require an operating voltage of 15 V and consume currents of 160 mA when fully loaded. They are available with positive or negative output voltage.
Flash LiDar Sensor
With a resolution of 2 x 192 pixels and noise < 50 cps, this 2D array opens up new perspectives for LiDAR-based systems in the automotive industry or gesture recognition.
SPAD2L192 is a 192 x 2 pixel solid-state CMOS sensor for flash LiDAR applications. The distance measurement is based on the first-photon direct time-of-flight principle. The single-photon detectors offer very high sensitivity and high timing resolution. The in-pixel time-to-digital converter with a resolution of 312.5 ps and a full-scale range of 1.28 µs enables flash ranging with a nominal operating range of 192 m and 4.7 cm resolution.
SPAD Evaluation Board
With the evaluation board, SPAD sensors for high-resolution imaging applications can be tested quickly and easily. A USB 2.0 interface facilitates data exchange with the application software.
The SPAD Evaluation Board provides reference voltages, data acquisition, sensor control, and two optional triggers. The sensor provides timing and counting mode to measure time between the start of measuring window and the first photon detection or the amount of detections inside a measurement window. The board supports USB 2.0 B data communication and is recognized as test and measurement device on the PC side.
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