Patent ID: 7737959

Claim:
A detection system, comprising: a substrate comprising a first surface, a second surface conceptually divided into multiple areas, and a third surface having first and second sections; a laser configured to emit electromagnetic radiation into the substrate via the first surface with subsequent incidence onto some areas of the second surface; and a sensor array configured to capture electromagnetic radiation reflected from the second surface and incident on the second section, wherein if a first dielectric having first dielectric constant is in contact with some areas, electromagnetic radiation incident thereon experiences total internal reflection and if a second dielectric having second dielectric constant is in contact with other areas, some of the electromagnetic radiation incident thereon is reflected back into the substrate by the second dielectric, wherein at least part of the first section is configured to reflect electromagnetic radiation incident thereon, and wherein the sensor array is configured to detect laser speckle originating from the incidence of the electromagnetic radiation at the second surface and to detect electromagnetic radiation reflected from the second dielectric, wherein the substrate is configured such that at least some of the electromagnetic radiation travels at least from the first surface directly to the second surface, then from the second surface directly to the third surface, and then from the third surface directly to the second surface before being captured at the sensor array, and wherein the substrate is configured such that the electromagnetic radiation that experiences the total reflection due to the first dielectric does not reach the second section of the third surface, the sensor array being positioned to receive only the electromagnetic radiation incident on the second section of the third surface, and wherein a first subsection of the first section of the third surface is a mirrored surface and a second subsection of the first section of the third surface is covered with a light absorbing material, the second subsection being positioned between the first subsection and the second section of the third surface.