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Quadrant & Array Photodiodes

Monolithic “quads” or quadrant photodiodes (QPDs) are 2 X 2 photodiode arrays with four planar diffused photodiode elements or segments. These are made using our silicon and 1.7μm InGaAs materials. In our 2.67μm InGaAs material, we can provide assembled quadrant photodiodes and arrays.

Marktech Optoelectronics quad photodiodes have low dark current, high resolution or precision, high accuracy, high response with low noise (high S/N ratio), wide spectral ranges, good frequency bandwidth, excellent dynamic range, minimal element spacing, low operating voltages, high shunt resistance, and large active areas. Marktech also manufactures both silicon and InGaAs linear arrays, which are used in dispersive spectroscopy and triangulation position sensing.

Military & Defence

Quad & Array Photodiodes

Product Photo Segments Peak Wavelength Size Active Area Spectral Range Specs Buy Now
MTPD4346T38-300 4, 2x2 1600 TO-5 Metal Can Flat Lens (8 pin) 3.0 mm 600-1750 Price Quote
MTSM2601SMF2-SP4-030 4, 2x2 1850 5.0x5.0 mm SMD Flat Lens 3.0 mm 800-2600 Price Quote
MT03-004 4, 2x2 940 TO-5 Metal Can Flat Lens (4 pin) 5.8 mm 400-1100 Digikey
MT03-072 4, 2x2 940 TO-8 Metal Can Flat Lens (6 pin) 50 mm2 350-1100 Digikey
MT03-081 4, 2x2 950 7.24x7.24 mm SMD Flat Lens 5.8 mm 350-1100 Price Quote

Product Information

Two segment, dual element, or bi-cell photodiodes are another type of position sensing device commonly incorporated into alignment or positioning systems. While quadrant photodiodes can sense position along two dimensions or both the X & Y axes, bi-element photodiodes align or position along one dimension or axis.


Marktech’s four-element photodiode arrays or quad detectors provide flawless performance in laser alignment and nanopositioning applications. Quadrant photodiodes (QPDs) or quadrant position sensitive detectors typically have resolutions as low as 10nm using beams with optical powers from 10 to 100microWatts. Quads can be used in auto-collimators for laser alignment, optical trackers, atomic force microscopes, scanning probe microscopes, stage positioners, surface profilometers, mask aligners, beam centering systems, fine sun sensors, ellipsometers, optical tweezers, tilt sensors, high accuracy displacement sensors, and other ultra-precision positioning applications. The fast response and wide operational bandwidth of QPDs have made these positioning devices dominant in the atomic force microscope (AFM) industry (Chien, et al.). Satellite communication systems can benefit from quadrant photodiodes as well. For example, quadrant photodiodes are key components in quadrant photoreceivers (QPRs) front-end devices for inter-satellite laser interferometry.

Both bi-cell and quadrant photodiodes are photodiode arrays (PDAs), with two (1X2) and four (2X2) elements, respectively. Bi and quad PDs are suitable for alignment or position sensing over a small beam displacement or position range. For laser or light beam position sensing over a larger range, longer, multi-element photodiode arrays are necessary. 

Marktech Optoelectronics also manufactures multi-element linear (one dimensional, 1D) and area (two dimensional, 2D) photodiode arrays with many segments for dispersive spectroscopy, refractometry, distance or range finding (triangulation position sensing), interferometry, and particle analyzers. Most photodiode arrays applications require custom-designed arrays and OEM integration, which is one of Marktech’s industry leading capabilities. Marktech’s detector experts have designed and manufactured photodiode arrays with 2, 4, 16, 20, 32, 64, and more elements.

Our InGaAs quadrant photodiodes and photodiode arrays have a wavelength sensitivity range from 600nm – 2600nm. Our silicon quadrant photodiodes and photodiode arrays have a wavelength sensitivity range from 250nm – 1100nm. These die can be packaged individually in a variety of hermetically sealed TO packages or integrated into a custom package (PLCC, COB, ATLAS hermetic SMD, ceramic carrier, etc.) to suit your specific application and pin-out design specs.


Analytical Instruments & Scientific Research

In scientific laboratories and research institutions, quadrant and linear photodetector arrays play a crucial role in measuring light intensity and wavelength. They are extensively used in fields such as spectroscopy and precision distance or position measurement to facilitate accurate data collection, enabling breakthroughs in physics, chemistry, biology, and more.


Quadrant photodetectors are commonly employed as “quadrant optical receivers in free space communications. The quadrant enables both tracking and data transmission between between satellites and between a satellite and earth stations.

Medical and Biotechnology

In the medical and biotechnology industries, silicon and InGaAs linear photodetector arrays are invaluable in diagnostic assays leveraging spectrometry methods.

Aerospace and Defense

Quadrant photodiodes are a key guidance element in missile systems. Quadrant mounted on the tip of a missile can track a spottiing laser beam on a target. Quadrant photodetectors are also extensively utilized in aerospace and defense laser based communications systems.

Environmental Monitoring

From monitoring air quality to studying climate change, silicon and InGaAs photodiode arrays enable precise measurement of light spectrums and particulate levels. IR spectroscopy relies on InGaAs arrays for gas sensing.

Distance & Position Sensing

Silicon and InGaAs quadrant and linear photodiode arrays are a key part of many photoelectric sensors, optical encoders, and range finders, which can precisely measure position, distances, angular position, and presence of objects. These end products are critical in the industrial automation, defense, and automotive fields.

Quadrant and Array Characteristics

The specific optical and electrical characteristics of our quadrant and linear photodiode arrays depend on the photodiode material used in construction. Marktech can provide monolithic and assembled quadrants and arrays in silicon and 1.7μm InGaAs.. For the  2.6μm InGaAs material, we only provide assembled quadrants and linear arrays, which can be more cost effective than monolithic version for applications with small annual requirements.

Additional Resources

Need Parts?

Do you need a small number of LEDs for your proof of concept? Or, are you looking to purchase a run for your prototypes? Visit our online stores at Digi-Key Electronics and Mouser Electronics today. In Japan, our products are now available through Rikei Corporation. In Israel, our products are now available through Militram. In Canada, our products are now available through ARL Group.

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