G01N 21/41
Refractivity
Official title: Refractivity; Phase-affecting properties, e.g. optical path length (G01N21/21 takes precedence)
G01N21/41 (Refractivity) appears on 2,178 US grants and 2,187 published applications in this corpus.
Search patents in G01N- Granted patents
- 2,178
- Published applications
- 2,187
- Assignees
- 1,366
- Inventors
- 5,290
- Latest grant
- 6 Oct 2026
Filings by year
| Year | Granted patents | Published applications |
|---|---|---|
| 1976 | 11 | 0 |
| 1977 | 7 | 0 |
| 1978 | 4 | 0 |
| 1979 | 3 | 0 |
| 1980 | 10 | 0 |
| 1981 | 14 | 0 |
| 1982 | 12 | 0 |
| 1983 | 10 | 0 |
| 1984 | 12 | 0 |
| 1985 | 14 | 0 |
| 1986 | 10 | 0 |
| 1987 | 28 | 0 |
| 1988 | 14 | 0 |
| 1989 | 28 | 0 |
| 1990 | 30 | 0 |
| 1991 | 39 | 0 |
| 1992 | 36 | 0 |
| 1993 | 22 | 0 |
| 1994 | 28 | 0 |
| 1995 | 31 | 0 |
| 1996 | 24 | 0 |
| 1997 | 25 | 0 |
| 1998 | 23 | 0 |
| 1999 | 15 | 0 |
| 2000 | 25 | 0 |
| 2001 | 22 | 6 |
| 2002 | 24 | 31 |
| 2003 | 23 | 43 |
| 2004 | 39 | 55 |
| 2005 | 31 | 48 |
| 2006 | 44 | 48 |
| 2007 | 37 | 59 |
| 2008 | 46 | 52 |
| 2009 | 46 | 69 |
| 2010 | 46 | 71 |
| 2011 | 41 | 66 |
| 2012 | 52 | 65 |
| 2013 | 54 | 85 |
| 2014 | 60 | 80 |
| 2015 | 62 | 94 |
| 2016 | 83 | 104 |
| 2017 | 87 | 91 |
| 2018 | 80 | 126 |
| 2019 | 124 | 142 |
| 2020 | 111 | 136 |
| 2021 | 98 | 146 |
| 2022 | 117 | 135 |
| 2023 | 105 | 132 |
| 2024 | 80 | 118 |
| 2025 | 113 | 98 |
| 2026 | 78 | 87 |
By publication year. Applications have been published since 2001. 2026 runs to 8 Oct.
Subgroups
Granted patents
- G01N 21/45Using interferometric methods995
- G01N 21/43By measuring critical angle392
- G01N 21/4133Refractometers345
- G01N 21/412Index profiling of optical fibres90
- G01N 2021/4126Index of thin filmsIndexing code44
- G01N 2021/4173Phase distributionIndexing code39
- G01N 2021/4106Atmospheric distortionIndexing code20
- G01N 2021/4166Methods effecting a waveguide mode enhancement through the property being measuredIndexing code16
All 9 subgroupsShow fewer
Recent patents
- Method and system for monitoring liquid-liquid extraction6 Oct 2026US 12,754,120 B2Triad National Security, LLC
- Refractive-index concentration sensor6 Oct 2026US 12,754,133 B2Keyence Corporation
- Observation device and observation method29 Sep 2026US 12,748,047 B2Hamamatsu Photonics K.K.
- Method for accumulating microscopic objects, and method for detecting microscopic objects using same29 Sep 2026US 12,748,113 B2University Public Corporation Osaka
- Method and system for evaluation of an interaction between an analyte and a ligand using a biosensor22 Sep 2026US 12,742,776 B2Cytiva Sweden AB
- Optical thin film analysis apparatus not affected by substrate back surface reflection and analysis method thereof8 Oct 2026US 2026/0309623 A1
- Interference observation device and interference observation method8 Oct 2026US 2026/0309643 A1Hamamatsu Photonics K.K.
- Method and apparatus for sensing a refractive disturbance1 Oct 2026US 2026/0298818 A1New Mexico Tech University Research Park Corporation
- Quantum absorption spectroscopy method and quantum absorption spectroscopy system1 Oct 2026US 2026/0298819 A1Kyoto University
- Waveguide for the analysis of biological samples24 Sep 2026US 2026/0287816 A1Bialoom Ltd
Most cited
By later US patents
- Compact moisture sensor with collimator lenses and prismatic coupler508US 5,661,303 ALibbey-Owens-Ford Co. · 1997
- Vehicular moisture sensor and mounting apparatus therefor456US 4,871,917 ADonnelly Corporation · 1989
- Optoelectronic sensor for detecting moisture on a windshield with means to compensate for a metallic layer in the windshield430US 5,498,866 ALeopold Kostal GmbH & Co. KG · 1996
- Method and apparatus for determining glucose concentration in a biological sample429US 5,710,630 ABoehringer Mannheim GmbH · 1998
- Vehicular moisture sensor and mounting apparatus therefor305US 4,973,844 ADonnelly Corporation · 1990