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Self-Balancing Position-Sensitive Detector (SBPSD).

Porrazzo R, Lydecker L, Gattu S, Bakhru H, Tokranova N, Castracane J - Sensors (Basel) (2015)

Bottom Line: Fabricated prototype devices demonstrate linear, symmetric coordinate characteristics and a spatial resolution of 200 μm for a 74 mm device.PSDs are commercially available only up to a length of 37 mm.Prototype devices were fabricated with various lengths up to 100 mm and can be scaled down to any size below that.

View Article: PubMed Central - PubMed

Affiliation: Colleges of Nanoscale Science and Engineering, SUNY Polytechnic Institute, 257 Fuller Road, Albany, NY 12222, USA. rporrazzo@albany.edu.

ABSTRACT
Optical position-sensitive detectors (PSDs) are a non-contact method of tracking the location of a light spot. Silicon-based versions of such sensors are fabricated with standard CMOS technology, are inexpensive and provide a real-time, analog signal output corresponding to the position of the light spot. An innovative type of optical position sensor was developed using two back-to-back connected photodiodes. These so called self-balancing position-sensitive detectors (SBPSDs) eliminate the need for external readout circuitry entirely. Fabricated prototype devices demonstrate linear, symmetric coordinate characteristics and a spatial resolution of 200 μm for a 74 mm device. PSDs are commercially available only up to a length of 37 mm. Prototype devices were fabricated with various lengths up to 100 mm and can be scaled down to any size below that.

No MeSH data available.


Related in: MedlinePlus

(A) Illustration of direction of current flow under illuminated light spot at the equilibrium position; (B) spatial distribution of the intensity of the light spot; (C) current produced in the device upon illumination in equilibrated state.
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sensors-15-17483-f002: (A) Illustration of direction of current flow under illuminated light spot at the equilibrium position; (B) spatial distribution of the intensity of the light spot; (C) current produced in the device upon illumination in equilibrated state.

Mentions: Potential difference between lines at each point across the device determines current direction at each location. The illuminated light spot creates a flow of current between the lines as shown in Figure 2. The generated currents automatically balance their flows around the median of the light spot. The equipotential is the position where the potential values of two lines are the same. At equilibrium the median of the light spot and the device equipotential are located at the same position, allowing for determination of the spot position relative to the device. The flow of current between the two lines causes the potential on the floating line to equilibrate to the same value as that of the biased line at the median of the light spot. At the equilibrium, the currents on both side of the center of the light spots are equal [17].


Self-Balancing Position-Sensitive Detector (SBPSD).

Porrazzo R, Lydecker L, Gattu S, Bakhru H, Tokranova N, Castracane J - Sensors (Basel) (2015)

(A) Illustration of direction of current flow under illuminated light spot at the equilibrium position; (B) spatial distribution of the intensity of the light spot; (C) current produced in the device upon illumination in equilibrated state.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4541945&req=5

sensors-15-17483-f002: (A) Illustration of direction of current flow under illuminated light spot at the equilibrium position; (B) spatial distribution of the intensity of the light spot; (C) current produced in the device upon illumination in equilibrated state.
Mentions: Potential difference between lines at each point across the device determines current direction at each location. The illuminated light spot creates a flow of current between the lines as shown in Figure 2. The generated currents automatically balance their flows around the median of the light spot. The equipotential is the position where the potential values of two lines are the same. At equilibrium the median of the light spot and the device equipotential are located at the same position, allowing for determination of the spot position relative to the device. The flow of current between the two lines causes the potential on the floating line to equilibrate to the same value as that of the biased line at the median of the light spot. At the equilibrium, the currents on both side of the center of the light spots are equal [17].

Bottom Line: Fabricated prototype devices demonstrate linear, symmetric coordinate characteristics and a spatial resolution of 200 μm for a 74 mm device.PSDs are commercially available only up to a length of 37 mm.Prototype devices were fabricated with various lengths up to 100 mm and can be scaled down to any size below that.

View Article: PubMed Central - PubMed

Affiliation: Colleges of Nanoscale Science and Engineering, SUNY Polytechnic Institute, 257 Fuller Road, Albany, NY 12222, USA. rporrazzo@albany.edu.

ABSTRACT
Optical position-sensitive detectors (PSDs) are a non-contact method of tracking the location of a light spot. Silicon-based versions of such sensors are fabricated with standard CMOS technology, are inexpensive and provide a real-time, analog signal output corresponding to the position of the light spot. An innovative type of optical position sensor was developed using two back-to-back connected photodiodes. These so called self-balancing position-sensitive detectors (SBPSDs) eliminate the need for external readout circuitry entirely. Fabricated prototype devices demonstrate linear, symmetric coordinate characteristics and a spatial resolution of 200 μm for a 74 mm device. PSDs are commercially available only up to a length of 37 mm. Prototype devices were fabricated with various lengths up to 100 mm and can be scaled down to any size below that.

No MeSH data available.


Related in: MedlinePlus