AMS Technologies offers an exceptionally large portfolio of silicon detectors and arrays. General-purpose photodiodes are available as well as diodes with particularly high speed or fast response behaviour, variants with wavelength-enhanced sensitivity or avalanche photodiodes (APDs).
Beyond single diodes (in TO-package or in chip or SMT configuration), AMS Technologies also supplies duo- and tetra-lateral detectors as well as multi-element photodiodes and arrays. In addition to the photodiode, our detector assemblies also include filters or multiple diodes in a sandwich design.
General-purpose Silicon Photodiodes
The planar diffused silicon photodiode series in packages like TO-5, TO-8, TO-18, low-Profile, BNC or plastic are suitable for high-speed and high-sensitivity applications. Additional series of general-purpose photodiodes are available in molded plastic, SMD 1206 and hermetic TO packages, designed for applications requiring low dark current, high reliability and high sensitivity. Industry standard silicon photodiodes are available in transparent or infrared transmitting, visible-blocking molded plastic packages.
AMS Technologies also carries further series of plastic molded silicon photodiodes in a variety of shapes and sizes of photodetectors and packages, including flat and lensed side lookers as well as surface mount versions, top or back illuminated. For customer-specific designs, we supply a selection of photodiode chips, including solderable silicon photodiode chip series offering a low-cost approach to applications requiring large active area photodetectors.
High-speed / Fast-response Silicon Photodiodes
A broad range of silicon PIN photodiodes is available in a wide variety of active areas to accommodate various applications – with the PIN structure allowing high quantum efficiency and fast response for detection of photons in the 400 to 1100 nm range. A series of high-speed silicon PIN photodiodes comprises small-area devices optimized for short response time or high-bandwidth applications, while a series of fast-response silicon photodiodes has been designed for low junction capacitance.
The family of large active area and high-speed silicon PIN photodiodes features a large sensing area optimized for short-haul optical data communication applications at 850 nm, high responsivity, wide bandwidth, low dark current as well as low capacitance at 3.3 V and is designed to match the most widely used transimpedance amplifiers.
Fully depleted photodiodes achieve the lowest possible junction capacitance and may be operated at a high reverse voltage, up to the maximum allowable value, for accomplishing even faster response times.
Wavelength-enhanced Silicon Photodiodes
Some of our silicon photodiode series are enhanced for a certain wavelength range, including detectors optimized for Nd-YAG lasers at 1060 nm, ambient light sensors with a response similar to the human eye, blue-enhanced silicon planar photodiodes designed for optimum response through the visible part of the spectrum, blue-enhanced photovoltaic detector series with high sensitivity in the visible-blue region and moderate response speeds, two series of planar diffused or inversion layer devices especially designed for low-noise detection in the UV region of the electromagnetic spectrum, or detectors that are soft x-ray, far-UV-enhanced.
Segmented or Multi-Element Silicon Detectors, Arrays
AMS Technologies’ portfolio of segmented, multi-element silicon detectors and arrays include common substrate photodetectors segmented into either two or four separate active areas, multi-element silicon array photodetectors, 4 by 4 two-dimensional silicon array detectors, a multi-channel x-ray detector as well as a series of x-ray photodiode arrays. Position sensing detectors are also available, based on duo-lateral or tetra-lateral technology.
Assemblies, Sandwich Detectors
AMS Technologies carries sets of detector-filter combinations incorporating a filter with a photodiode to achieve a tailored spectral response, including dedicated combinations for a spectral response approximating that of the human eye. The series of dual sandwich detectors or two-color detectors are mostly employed for remote temperature measurements.
A series of general-purpose silicon photodiode-amplifier hybrids is available, combining a photodiode with an operational amplifier in the same package, plus a special version for 850 nm high-speed fiber optic data communication. A series of position sensing modules combines quadrant photodiode arrays with associated circuitry on a PCB to provide two difference signals and a sum signal. The series of self-contained single photon counting modules meets low-light-level detection demands. Special combinations of photodiodes and IREDs as well as custom assemblies address the requirements of electro-optical smoke detectors.
Silicon Avalanche Photodiodes (APDs)
AMS Technologies provides silicon avalanche photodiodes in broad variety of sizes, packages and configurations, including a series of high-volume, cost-effective silicon APDs, based on the internal gain mechanism for fast time response, low dark current and high sensitivity in the near infrared region, and “800 nm optimized” silicon APDs, available in hermetic metal packages. Our series of high-performance silicon avalanche photodiodes features low noise, high quantum efficiency and high gain while maintaining reasonably low operating voltage. Based on our series of standard silicon APDs, customized versions are available on request.
Wavelength-enhanced Silicon Avalanche Photodiodes (APDs)
Using a double-diffused “reach-through” structure, an APD series with an enhanced 1064 nm long-wave response is available. Our series of large-area, UV-enhanced silicon avalanche photodiodes is intended for use in a wide variety of broadband low-light-level applications covering the spectral range from below 400 to beyond 700 nm.
Silicon Avalanche Photodiode (APD) Arrays and Assemblies
AMS Technologies carries a family of avalanche photodiode (APD) arrays and quadrants that provides ultra-high sensitivity at 400 to 1000 nm. The hybrid optical APD receiver modules are comprised of a photodetector and a transimpedance amplifier in the same hermetically sealed package, reducing noise pickup from the surrounding environment and parasitic capacitance from interconnect, thus allowing lower-noise operation.
Complementing our silicon detectors and arrays, AMS Technologies also offers a broad range of additional discrete detectors and arrays based on other materials like InGaAs or PbS/PbSe that are suitable for higher wavelengths further into the infrared domain. Other discrete detectors and arrays available from AMS Technologies include devices based on materials like HgCdTe, InAs/InAsSb or GaAs, but also balanced photodetectors, integrated optical receiver modules or infrared detection modules.
Guiding and focusing light onto optical detectors can be done using AMS Technologies’ broad portfolio of optics components like optical lenses, optical filters or optical windows, as well as our optical fibers.
The essential component of silicon (Si) detectors and arrays is usually a silicon photodiode – a silicon-based semiconductor light sensor. Light falling on the p-n or PIN junction within the active area of a photodiode generates an electric current due to the internal photoelectric effect (for details see Discrete Detectors and Arrays). At room temperature, silicon has a band gap of 1.12 eV between the valence band and the conduction band, so particles or photons that can create an electron/hole pair (and thus a photovoltage) in silicon must have an energy greater than 1.12 eV - which in turn corresponds to a wavelength of less than 1100 nm. The sensitivity range of silicon photodiodes is approximately between 190 and 1100 nm.
Key properties of silicon photodiodes are the size of the sensor’s active area, the spectral wavelength range, the radiometric sensitivity (photocurrent intensity per incident light power, in A/W), the wavelength with the highest sensitivity (peak wavelength), the average noise power (NEP, Noise Equivalent Power, in W/√Hz) and the maximum dark current. Silicon photodiodes are available in a wide variety of sizes, designs and packages, from hermetically sealed TO packages to plastic molded devices and SMT designs to solderable or bondable chips.
Multi-element Silicon Detectors, Arrays, PSDs
While multi-element silicon detector arrays are made of multiple, lined-up, separate photodiodes, position sensing detectors (PSDs) consist of a sensor surface that is either segmented or utilizes the lateral effect to determine the exact position at which a light beam hits the sensor.
In segmented PSDs, the common photodiode substrate is usually divided into two (one-dimensional) or four segments of equal size, separated by a gap or dead region. For correct operation, the diameter of the light beam to be measured must be larger than this gap, and the beam has to hit at least parts of all of the segments.
Lateral-effect PSDs, on the other hand, consist of a single planar diffused photodiode area without gaps or dead zones. The position of a light beam impinging anywhere on the surface of the PSD is determined by the height of the photocurrents through various contacts at the edge of the detector. Duo-lateral PSDs pass the photocurrent through two resistive layers, one on top of the photodiode and one below it. Tetra-lateral PSDs have only one resistive layer and therefore exhibit higher non-linearity as well as greater errors in position determination.
While segmented PSDs are characterized by higher accuracy under optimal boundary conditions, lateral-effect PSDs offer a wider dynamic range and are independent of the profile and intensity distribution of the light spot.
Silicon Avalanche Photodiodes (APDs)
Avalanche photodiodes (APDs) have a higher sensitivity and a higher speed compared to standard silicon diodes. In addition to the internal photoelectric effect generating a photocurrent, these components use the avalanche effect for internal amplification. Silicon APDs are suitable as detectors for extremely low-intensity radiation and even single photon counting in the visible and near-infrared domain (400 to 1100 nm).
Silicon photodiodes are used in a wide range of applications such as spectroscopy, medical imaging, laser beam alignment, analytics, surface characterization, optical position sensing or optical communication.
Alternative Terms: Silicon Optical Detector; Silicon Optical Array; Silicon Avalanche Photodiode; Si APD; Si Detector Module; Silicon PSD