Annular solid immersion lenses and methods of making them

Abstract

A sub-millimeter solid immersion lens (SIL), comprises a body of a high-index material transparent to electromagnetic radiation in a frequency band to be observed, the body having a flat bottom surface which receives an object to be observed, and the body further having a first upper surface whose limits approximate a zone of a spherical segment and a second upper surface defined by an upper bound of the zone of the spherical segment which prevents passage of electromagnetic radiation in the frequency band to be observed. The SIL may be incorporated into an array, according to other aspects. A method of making a SIL comprises: providing a substrate layer of a high-index material transparent to electromagnetic radiation in a frequency band to be observed, having a lower surface through which an object is observed; etching a surface of the substrate layer to form a first upper surface whose limits approximate a zone of a spherical segment; etching a surface of the substrate layer to form a second upper surface; treating the second upper surface to prevent transmission of the electromagnetic radiation in the frequency band to be observed; and treating the lower surface to absorb electromagnetic radiation in the frequency band to be observed, leaving untreated a hole defined therein to form a sampling port at which the object is positioned.

Dependencies are inferred from the claim text.