Abstract
We have proposed and demonstrated position-sensitive detectors based on the spectral changes in fluorescent waveguides. The first prototype is a transparent heat-shrink tubing containing an organic luminescent dye at its core. With a laser beam incident on this linear fluorescent tubing, the redshift in the photoluminescence (PL) spectrum observed at its edge increases with the distance from the incident point. The range for position sensing is 2 cm. It is extended to 280 cm by adopting a scintillating fiber in our second experiment. Two-stage conversion enables two-dimensional position detection. We have attached two linear fluorescent tubing to a planar 50 mm × 50 mm × 8 mm fluorescent waveguide. When a laser beam excites the first luminescent material at a single spot in the planer waveguide, PL photons propagate to its edges and excite the second luminescent material in the two linear waveguides. Photon division between these linear waveguides gives the first coordinate. The second coordinate is given by the redshift in the linear waveguides. We have observed that the maximum error in position estimation is 1.5 mm. Unlike the conventional semiconductor technologies, no electronic components are required for the sensor head. This robust technology might be suited for deployment in large-scale harsh environments.
Highlights
A position-sensitive detector (PSD) has been utilized in various applications
In an atomic force microscope, a cantilever hanging over a specimen reflects a laser beam and a PSD detects the reflected beam
In high-energy physics experiments, a PSD tracks a beam of particles or electromagnetic radiation
Summary
A position-sensitive detector (PSD) has been utilized in various applications. For example, a beam of light irradiates an object on a belt in an assembly line and a PSD detects the reflected light and generates feedback signals for automatic control. In many PSDs, a semiconductor material converts the incoming radiation to electric charges and the charge division between multiple electrodes gives the position of the incident spot.[1,2,3] Even when multiple light beams hit different spots on a PSD simultaneously, one can detect their positions by modulating the light sources.[4] In general, a semiconductor device is small and expensive.[5] Onedimensional (1-D) PSDs are commercially available only up to a length of 37 mm.[6] In laboratory experiment, a PSD with a sensitive length of 74 mm is reported.[6] an organic/inorganic hybrid sensor structure might have the advantage of low temperature and simple fabrication process,[7] for a large-scale implementation, the use of a semiconductor substrate would be prohibitively expensive. We exploit lasers in our experiments to demonstrate this position-sensing principle in the visible range
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
