arXiv subjects

H. John Caulfield

Publications and source records attributed to H. John Caulfield.

3 recordsLinked to original sources

arXiv2013

Artificial color perception using microwaves

We report the feasibility of artificial color perception under microwave illumination using a standard microwave source and an antenna. We have sensed transmitted microwave power through color objects and have distinguished the colors by analyzing the sensed transmitted power. Experiments are carried out using a Gunn diode as the microwave source, some colored liquids as the objects and a microwave diode as the detector. Results are presented which open up an unusual but new way of perceiving colors using microwaves.

physics.optics↗

arXiv2008

Optics-less smart sensors and a possible mechanism of cutaneous vision in nature

Optics-less cutaneous (skin) vision is not rare among living organisms, though its mechanisms and capabilities have not been thoroughly investigated. This paper demonstrates, using methods from statistical parameter estimation theory and numerical simulations, that an array of bare sensors with a natural cosine-law angular sensitivity arranged on a flat or curved surface has the ability to perform imaging tasks without any optics at all. The working principle of this type of optics-less sensor and the model developed here for determining sensor performance may be used to shed light upon possible mechanisms and capabilities of cutaneous vision in nature.

physics.optics↗

arXiv2007

Computational Vision in Nature and Technology

It is hard for us humans to recognize things in nature until we have invented them ourselves. For image-forming optics, nature has made virtually every kind of lens humans have devised. But what about lensless "imaging"? Recently, we showed that a bare array of sensors on a curved substrate could achieve resolution not limited by diffraction- without any lens at all provided that the objects imaged conform to our a priori assumptions. Is it possible that somewhere in nature we will find this kind of vision system? We think so and provide examples that seem to make no sense whatever unless they are using something like our lensless imaging work.

physics.optics↗