# US 12,761,464 B2 · Getter vacuum pump to maintain vacuum pressure within a housing of a Fabry-Perot cavity > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 12,761,464 B2 - Document ID: US12761464B2 - Status: Granted - Kind: B2 - Application number: 18/493,550 - Filed: 2023-10-24 - Published: 2024-05-02 - Granted: 2026-10-13 - Earliest claimed: 2022-10-28 - Assignees: Stable Laser Systems, Inc. - Applicants: Stable Laser Systems, Inc. - Inventors: Mark Notcutt; Josue Davila-Rodriguez; William David Lee - Web page: https://patentgrep.com/patent/US12761464B2 ## CPC - G02B 26/001: {based on interference in an adjustable optical cavity (interference filters G02B5/28; devices or arrangements using multiple reflections in spectrometry or monochromators G01J3/26)} - G02B: OPTICAL ELEMENTS, SYSTEMS OR APPARATUS ## Abstract Methods and systems for controlling and maintaining the pressure in an ultra-stable optical resonance cavity are disclosed herein. A method for controlling and maintaining the pressure in an ultra-stable optical resonance cavity, for example, comprises providing an ultra-stable optical system housed in a vacuum housing enclosure and a pumping system in communication with the vacuum housing for maintaining a pressure in the vacuum housing less than 1×10−6 Torr. The pumping system may comprise combination pumping achieved with the simultaneous use of a getter pump and an ion pump that provide passive and active pumping, respectively. The pumping system may also comprise passive pumping only with a getter vacuum pump only. The present invention, disclosed herein, achieves passive, power-free pumping in ultra-stable laser systems thereby enhancing the portability of such systems. ## Claims ### Claim 1 An optical system comprising: a first reflector; a second reflector in optical communication with the first reflector; a spacer having a first end and a second end provided between the first reflector and the second reflector; wherein the first reflector is positioned at the first end of the spacer and the second reflector is positioned at the second end of the spacer to provide an optical path length between the first reflector and the second reflector; wherein the first reflector and the second reflector are positioned such that the first reflector and the second reflector intersect an incident light beam, thereby forming an optical resonance cavity between the first reflector and the second reflector; a vacuum housing enclosing the optical resonance cavity; a pumping system in communication with the vacuum housing for maintaining a pressure in the vacuum housing less than 1×10−6 Torr; the pumping system comprising a getter pump; the getter pump being configured to maintain the pressure inside the vacuum housing at or below 1×10−6 Torr after evacuation; and wherein the optical resonance cavity is a Fabry-Perot cavity, an ultra-stable cavity, or a vacuum gap cavity. ### Claim 2 (depends on 1) The optical system of claim 1, wherein said getter pump comprises an evaporable getter pump. ### Claim 3 (depends on 1) The optical system of claim 1, wherein said getter pump comprises a non-evaporable getter (NEG) pump. ### Claim 4 (depends on 1) The optical system of claim 1, wherein the pumping system further comprises an ion pump. ### Claim 5 (depends on 1) The optical system of claim 1, wherein the pumping system does not comprise an ion pump. ### Claim 6 (depends on 1) The optical system of claim 1, wherein said optical resonance cavity is a space-vented cavity in low-earth orbit. ### Claim 7 (depends on 1) The optical system of claim 1, wherein the pumping system provides a constant pressure of the optical resonance cavity. ### Claim 8 (depends on 7) The optical system of claim 7, wherein the constant pressure of the optical resonance cavity is characterized by variations of less than 3×10−9 Torr in 1 s. ### Claim 9 (depends on 1) The optical system of claim 1, wherein the getter pump is characterized by a pumping speed selected over the range of 1 l/s to 500 l/s. ### Claim 10 (depends on 1) The optical system of claim 1, wherein the getter pump is characterized by a sorption capacity selected over the range of 0.005 Torr·l to 1,000 Torr·l. ### Claim 11 (depends on 1) The optical system of claim 1, wherein the getter pump is provided within the vacuum housing. ### Claim 12 (depends on 11) The optical system of claim 11, wherein said getter pump comprises a non-evaporable getter (NEG) pump; and wherein the NEG pump is provided as a coating on a portion of an internal surface of the vacuum housing exposed to the optical resonance cavity. ### Claim 13 (depends on 12) The optical system of claim 12, wherein the NEG pump comprises one or more porous metals, alloys, or metal oxides. ### Claim 14 (depends on 12) The optical system of claim 12, wherein the NEG pump comprises Al, Zr, Ti, V, or Fe. ### Claim 15 (depends on 11) The optical system of claim 11, wherein said getter pump comprises an evaporable getter pump. ### Claim 16 (depends on 15) The optical system of claim 15, wherein the evaporable getter pump comprises one or more of metals, alloys, and metal oxides. ### Claim 17 (depends on 15) The optical system of claim 15, wherein the evaporable getter pump comprises Ba(N3)2, Ta, Nb, Zr, Th, Ti, Al, Mg, Ba, or P. ### Claim 18 (depends on 1) The optical system of claim 1, wherein the getter pump is configured to maintain the pressure in the vacuum housing at or below 1×10−6 Torr for a duration of at least 80 hours. ### Claim 19 A method of controlling pressure in an ultra-stable optical resonance cavity, the method comprising: providing the ultra-stable cavity enclosed in a vacuum housing; wherein the ultra-stable cavity comprises: a first reflector; a second reflector in optical communication with the first reflector; a spacer having a first end and a second end provided between the first reflector and the second reflector; wherein the first reflector is positioned at the first end of the spacer and the second reflector is positioned at the second end of the spacer to provide an optical path length between the first reflector and the second reflector; wherein the first reflector and the second reflector are positioned such that the first reflector and the second reflector intersect an incident light beam, thereby forming the ultra-stable optical resonance cavity between the first reflector and the second reflector; maintaining a pressure in the vacuum housing less than 1×10−6 Torr using a pumping system in communication with the vacuum housing; wherein the pumping system comprises a getter pump, the getter pump maintaining the pressure inside the vacuum housing at or below 1×10−6 Torr after evacuation; and wherein the optical resonance cavity is a Fabry-Perot cavity, an ultra-stable cavity, or a vacuum gap cavity. ### Claim 20 (depends on 19) The method of claim 19, wherein said getter pump comprises an evaporable getter pump. ### Claim 21 (depends on 19) The method of claim 19, wherein said getter pump comprises a non-evaporable (NEG) getter pump. ### Claim 22 A method of transporting an ultra-stable optical resonance cavity, the method comprising: providing the ultra-stable cavity enclosed in a vacuum housing; wherein the ultra-stable cavity comprises: a first reflector; a second reflector in optical communication with the first reflector; a spacer having a first end and a second end provided between the first reflector and the second reflector; wherein the first reflector is positioned at the first end of the spacer and the second reflector is positioned at the second end of the spacer to provide an optical path length between the first reflector and the second reflector; wherein the first reflector and the second reflector are positioned such that the first reflector and the second reflector intersect an incident light beam, thereby forming the ultra-stable optical resonance cavity between the first reflector and the second reflector; pumping said vacuum enclosure during transport using a pumping system in fluid communication with the vacuum housing so as to maintain a pressure in the vacuum housing less than 1×10−6 Torr; wherein the pumping system comprises a getter pump, the getter pump maintaining the pressure inside the vacuum housing at or below 1×10−6 Torr after evacuation; and wherein the optical resonance cavity is a Fabry-Perot cavity, an ultra-stable cavity, or a vacuum gap cavity. ### Claim 23 (depends on 22) The method of claim 22, wherein said getter pump comprises an evaporable getter pump. ### Claim 24 (depends on 22) The method of claim 22, wherein said getter pump comprises a non-evaporable getter pump.