US 11,674,888 B2
Self-aligned high finesse optical sensor cell
Kelly Pickrell, Calgary (CA); Charles Anim Odame-Ankrah, Calgary (CA); and Brian Wayne Rosentreter, Calgary (CA)
Assigned to GLOBAL ANALYZER SYSTEMS LIMITED, Calgary (CA)
Appl. No. 17/257,471
Filed by GLOBAL ANALYZER SYSTEMS LIMITED, Calgary (CA)
PCT Filed Jul. 3, 2019, PCT No. PCT/CA2019/050917
§ 371(c)(1), (2) Date Dec. 31, 2020,
PCT Pub. No. WO2020/006633, PCT Pub. Date Jan. 9, 2020.
Claims priority of provisional application 62/693,594, filed on Jul. 3, 2018.
Prior Publication US 2021/0131947 A1, May 6, 2021
Int. Cl. G01N 21/01 (2006.01); G01N 21/25 (2006.01); G02B 5/10 (2006.01)
CPC G01N 21/01 (2013.01) [G01N 21/255 (2013.01); G02B 5/10 (2013.01)] 20 Claims
OG exemplary drawing
 
1. A high finesse optical sensor cell for analyzing a gaseous sample using a light source, comprising:
a housing defining a linear optical cavity, having an optical axis extending between a first open end portion and a second open end portion of the housing, the housing comprising:
a first set of contact geometry located adjacent to a first end of the optical cavity, and a second set of contact geometry located adjacent to a second end of the optical cavity, wherein at least the first set of contact geometry is radially symmetrical about the optical axis, and wherein the first set of contact geometry defines a planar contact surface that is perpendicular to the optical axis of the optical cavity,
the first and second ends of the optical cavity being located within the first and second open end portions of the housing, respectively, and
an inlet port and an outlet port for conveying the gaseous sample into and out of the optical cavity;
a first highly reflective (HR) mirror assembly comprising:
a first HR mirror having a concave reflective surface, wherein the first set of contact geometry is adapted to contact the concave reflective surface of the first HR mirror; and
a first end cover being configured for removable attachment to the first open end portion of the housing and to maintain the concave reflective surface of the first HR mirror in contact with the first set of contact geometry, the first end cover having an opening for receiving an entrant beam of light coincident with the optical axis,
a second HR mirror assembly comprising:
a second HR mirror having a reflective surface, wherein the second set of contact geometry is adapted to contact the reflective surface of the second HR mirror;
a second end cover being configured for removable attachment to the second open end portion of the housing and to maintain the reflective surface of the second HR mirror in contact with the second set of contact geometry, the second end cover having an opening for emitting the beam of light to a detector coincident with the optical axis;
wherein the sensor cell further comprises:
a first sealing member to create a seal between the first end of the optical cavity and the reflective surface of the first HR mirror, and
a second sealing member to create a seal between the second end of the optical cavity and the reflective surface of the second HR mirror;
wherein the center of curvature of the first concave HR mirror is maintained in alignment (coincident) with the optical axis of the optical cavity without requiring mechanical adjustment.