Fabry-perot cavity fabrication using shadow masking
US20260063847A1
Abstract
A process for creating a Fabry-Perot Cavity (FPC) sensor using Two-Photon Polymerization (2PP) includes: fabricating a mask directly on a cleaved tip of a fiber optic cable. The mask includes: a beveled central hole aligned over the core of the fiber optic cable, side extensions that extend radially beyond a cladding of the fiber optic cable. The process includes sputtering a first reflective coating over the mask and tip of the fiber optic cable, mechanically removing the mask using the side extensions, and fabricating a resonator cavity structure (RCS) using a 2PP process over the gold disc.
Description (excerpt)
Pursuant to 37 C.F.R. § 1.78 (a)(4), this application claims the benefit of and priority to prior filed co-pending Provisional Application Ser. No. 63/690,042, filed Sep. 3, 2024, which is expressly incorporated herein by reference in its entirety. RIGHTS OF THE GOVERNMENT The invention described herein may be manufactured and used by or for the Government of the United States for all governmental purposes without the payment of any royalty. FIELD OF THE INVENTION The present invention relates generally to Fabry-Perot cavity fabrication and, more particularly, to Fabry-Perot cavity fabrication using shadow masking and two-photon polymerization. BACKGROUND OF THE INVENTION As computers continue to improve and model the real world more and more accurately, it is important to measure the world as accurately as possible. For each situation, the best measurement will depend on many factors, but often, it comes down to having the most accurate data possible, and having as many accurate measurements as can be processed. Accurate and repeated measurements of physical phenomenon are crucial to intelligent decision making and automation. Sensors are like the eyes and ears of computers in the physical world, but modern sensors can sense phenomena far beyond human senses. However, when designing a system, it is important to consider the size, weight, and power (SWAP) requirements of every single component. Minimizing size, weight, and power while keeping the same or higher degree of sensitivity enables extra design flexibility in highly optimized devices, such as satellites. Minimizing the requirements of a sensor could enable more low SWAP sensors in a system, which would provide a more complete picture to the system. Alternatively, low SWAP sensors could mean adding more mission critical capabilities. This paper explores micro-optical Fabry-Perot Cavity (FPC) sensors fabricated with multi-step 2-photon polymerization (2PP) techniques. The process enables quality factors an order of magnitude greater than other 2PP sensors and enables exploration of other sensor geometries. SUMMARY OF THE INVENTION The present invention overcomes the foregoing problems and other shortcomings, drawbacks, and challenges of sensor fabrication. While the invention will be described in connection with certain embodiments, it will be understood that the invention is not limited to these embodiments. To the contrary, this invention includes all alternatives, modifications, and equivalents as may be included within the spirit and scope of the present invention. According to one embodiment of the present invention a process for creating a Fabry-Perot Cavity (FPC) sensor using Two-Photon Polymerization (2PP) includes: fabricating a mask directly on a cleaved and flat tip of a fiber optic cable, wherein the mask includes: a beveled central hole aligned directly over the core of the fiber optic cable; and side extensions that extend radially beyond a cladding of the fiber optic cable with respect to a central axis of the mask; sputtering a first reflective coating over the mask and tip of the fiber optic cable such that the first reflective coating adheres to the mask where the mask covers the tip and adheres to the core of the fiber optic cable where the tip is exposed; mechanically removing the mask using the side extensions such that the first reflective coating adhered to the fiber optic cable remains as a precisely centered gold disc on the tip; fabricating a resonator cavity structure (RCS) using a 2PP process over the gold disc, wherein the RCS includes a RCS tip; sputtering a second reflective coating over the RCS tip, wherein the second reflective coating adheres to an external surface of the RCS tip. The first reflective coating and the second reflective coating are aligned in parallel such that the resonator cavity structure acts as an FPC when light passes along the fiber optic cable and through the first reflective coating. According to another embodiment of the present invention, a process for creating a Fabry-Perot Cavity (FPC) sensor using Two-Photon Polymerization (2PP) includes: fabricating a mask directly on a cleaved and flat tip of a fiber optic cable, wherein the mask includes: a beveled central hole aligned directly over the core of the fiber optic cable; and side extensions that extend radially beyond a cladding of the fiber optic cable with respect to a central axis of the mask; sputtering a first reflective coating over the mask and tip of the fiber optic cable such that the first reflective coating adheres to the mask where the mask covers the tip and adheres to the core of the fiber optic cable where the tip is exposed; mechanically removing the mask using the side extensions such that the first reflective coating adhered to the fiber optic cable remains as a precisely centered
Filing details
- Inventors
- Hengky CHANDRAHALIM
- Assignee
- Government Of The United States As Represented By The Secretary Of The Air …
- Filed
- Jun 9, 2025
- Granted
- Application pending
Bibliographic data and excerpted text sourced from Google Patents (public record) as part of IP TechMatch's current-filings monitor. This filing is not part of the 2019 historical archive. For the authoritative full text, drawings, and legal status, see the source links above or consult USPTO records directly.