IP Library › Granted Patent US 12,204,129
Granted Patent B2
US 12,204,129 · App. 18/471,740 · Granted Jan 21, 2025

Stacked waveguides having different diffraction gratings for combined field of view

Inventors: Chulwoo Oh (Sammamish, WA); Vikraman Parthiban (Austin, TX)
Assignee: Magic Leap, Inc.
G02B6/0016G02B5/1833G02B5/1842G02B6/0076G02B6/10G02B27/0093G02B27/0172G02B27/0189G02B27/4261G02F1/292H04N9/3129G02B2027/0123G02B2027/0127G02B2027/0134G02B2027/0185G02B2027/0187G02F2201/305G02F2203/22
View Patent ↗
Loading inventors, assignments & file history…
Monitor This Case
Get email alerts when status or documents change.
Order Certified Copies
Most orders are placed with the USPTO same day — all within 24 business hours.
Order via The Patent Place →
Pre-filled with this patent's details
Quick Facts
Patent No.
US 12,204,129
App. No.
18/471,740
Granted
Jan 21, 2025
Kind
B2
Abstract

In one aspect, an optical device comprises a plurality of waveguides formed over one another and having formed thereon respective diffraction gratings, wherein the respective diffraction gratings are configured to diffract visible light incident thereon into respective waveguides, such that visible light diffracted into the respective waveguides propagates therewithin. The respective diffraction gratings are configured to diffract the visible light into the respective waveguides within respective field of views (FOVs) with respect to layer normal directions of the respective waveguides. The respective FOVs are such that the plurality of waveguides are configured to diffract the visible light within a combined FOV that is continuous and greater than each of the respective FOVs.

Claims (23)

1. An optical device, comprising:

a plurality of waveguides formed over one another and having formed thereon respective diffraction gratings, wherein the respective diffraction gratings are configured to diffract visible light incident thereon into respective waveguides, such that visible light diffracted into the respective waveguides propagates therewithin,

wherein the respective diffraction gratings are configured to diffract the visible light incident on the respective waveguides within respective field of views (FOVs) into the respective waveguides with respect to layer normal directions of the respective waveguides, and wherein the respective FOVs are such that the plurality of waveguides are configured to diffract the visible light within a combined FOV that is continuous and greater than each of the respective FOVs,

wherein the plurality of waveguides includes a first waveguide having formed thereon a first diffraction grating configured to partially diffract and to partially transmit the visible light incident thereon, and includes a second waveguide having formed thereon a second diffraction grating configured to at least partially diffract the transmitted visible light from the first diffraction grating incident thereon, and

wherein the first and second diffraction gratings have different periods and are configured to diffract visible light having different wavelengths and different colors,

wherein the first diffraction grating has a first period and is configured to diffract visible light having a first color, and wherein the second grating has a second period and is configured to diffract visible light having the first color and visible light having a second color, wherein the first color corresponds to a shorter wavelength than the second color,

wherein the first diffraction grating is configured to partially diffract visible light having the first color incident thereon within a first FOV with a diffraction efficiency exceeding about 80%, and to partially transmit the visible light having the first color incident thereon within a second FOV with a transmission efficiency exceeding about 80%,

and wherein the second diffraction grating is configured to at least partially diffract the visible light having the first color partially transmitted through the first diffraction grating within the second FOV with a diffraction efficiency exceeding about 80%,

wherein the first diffraction grating is configured to substantially transmit the visible light having the second color within the first FOV, and wherein the second diffraction grating is configured to at least partially diffract the visible light having the second color incident within the first FOV,

wherein the first diffraction grating comprises periodically varying liquid crystals arranged to have a first period in a lateral direction, and wherein the second diffraction grating comprises periodically varying liquid crystals arranged to have a second period in the lateral direction that is greater than the first period, and

wherein the periodically varying liquid crystals of the first diffraction grating have a helical pitch that is smaller than a helical pitch of the periodically varying liquid crystals of the second diffraction grating.

2. The optical device of claim 1 , wherein the liquid crystal diffraction gratings comprise cholesteric liquid crystals.

3. The optical device of claim 1 , wherein the first diffraction grating has a wavelength/period ratio N/A between about 0.5 and 0.8, wherein λ is a wavelength of light partially diffracted by the first grating, and wherein A is the period of the first diffraction grating.

4. The optical device of claim 1 , wherein the second diffraction grating has a wavelength/period ratio N/A between about 0.5 and 0.8, wherein 2 is a wavelength of light partially diffracted by the second grating, and wherein A is the period of the second diffraction grating.

5. The optical device of claim 1 , wherein one or both of the first diffraction grating and the second diffraction grating are configured to diffract light into the respective waveguides transmissively.

6. The optical device of claim 1 , wherein one or both of the first diffraction grating and the second diffraction grating are configured to diffract light into the respective waveguides reflectively.

7. The optical device of claim 1 , wherein the first diffraction grating is configured to diffract visible light having a first color, and wherein the second diffraction grating is configured to diffract visible light having a second color, wherein the first color is green and the second color is red.

8. The optical device of claim 1 , wherein the first diffraction grating is configured to diffract visible light having a first color, and wherein the second diffraction grating is configured to diffract visible light having a second color, wherein the first color is blue and the second color is green.

9. The optical device of claim 1 , wherein the plurality of waveguides are formed of a material whose refractive index is smaller than an effective refractive index of the respective diffraction gratings, such that the visible light diffracted into the respective waveguides propagates therewithin under total internal reflection.

10. The optical device of claim 1 , wherein the plurality of waveguides are in a stacked arrangement and are configured to propagate the visible light in substantially parallel directions under total internal reflection.

11. The optical device of claim 1 , wherein different ones of the respective diffraction gratings are disposed to overlap each other in a lateral direction perpendicular to the layer normal directions.

12. The optical device of claim 1 , wherein different ones of the respective FOVs do not overlap by more than 20% on the basis of a sum of the different ones of the respective FOVs.

13. The optical device of claim 1 , comprising a third waveguide having formed thereon a third diffraction grating having a third period and configured to diffract visible light having a third color, wherein the second color corresponds to a shorter wavelength than the third color.

Assignments (3)
SECURITY INTEREST Recorded Oct 31, 2025
From: MAGIC LEAP, INC.; MENTOR ACQUISITION ONE, LLC; MOLECULAR IMPRINTS, INC.
To: CITIBANK, N.A., AS COLLATERAL AGENT
Reel/Frame 073422/0549 →
SECURITY INTEREST Recorded Oct 20, 2025
From: MAGIC LEAP, INC.; MENTOR ACQUISITION ONE, LLC; MOLECULAR IMPRINTS, INC.
To: CITIBANK, N.A., AS COLLATERAL AGENT
Reel/Frame 073031/0206 →
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Sep 27, 2023
From: OH, CHULWOO; PARTHIBAN, VIKRAMAN
To: MAGIC LEAP, INC.
Reel/Frame 065042/0697 →
Continuity (4)
Division 17590482 · Feb 1, 2022
Division 15926920 · Mar 20, 2018
Provisional Application 62474529 · Mar 21, 2017
Related Publication 20240012191A1 · Jan 11, 2024
References Cited (167)
US 4991924A · Shankar et al. · 1991 [cited by applicant]
US 5808797A · Bloom et al. · 1998 [cited by applicant]
US 6188462B1 · Lavrentovich et al. · 2001 [cited by applicant]
US 6850221B1 · Tickle · 2005 [cited by applicant]
US 6982818B2 · Riza et al. · 2006 [cited by applicant]
US D514570S · Ohta · 2006 [cited by applicant]
US 7206107B2 · Levola · 2007 [cited by applicant]
US 7375784B2 · Smith et al. · 2008 [cited by applicant]
US 7573640B2 · Nivon et al. · 2009 [cited by applicant]
US 7705943B2 · Kume et al. · 2010 [cited by applicant]
US 8233204B1 · Robbins et al. · 2012 [cited by applicant]
US 8339566B2 · Escuti et al. · 2012 [cited by applicant]
US 9081426B2 · Armstrong · 2015 [cited by applicant]
US 9195092B2 · Escuti et al. · 2015 [cited by applicant]
US 9215293B2 · Miller · 2015 [cited by applicant]
US D752529S · Loretan et al. · 2016 [cited by applicant]
US 9345402B2 · Gao · 2016 [cited by applicant]
US 9348143B2 · Gao et al. · 2016 [cited by applicant]
US D758367S · Natsume · 2016 [cited by applicant]
US D759657S · Kujawski et al. · 2016 [cited by applicant]
US 9417452B2 · Schowengerdt et al. · 2016 [cited by applicant]
US 9470906B2 · Kaji et al. · 2016 [cited by applicant]
US 9547174B2 · Gao et al. · 2017 [cited by applicant]
US 9671566B2 · Abovitz et al. · 2017 [cited by applicant]
US D794288S · Beers et al. · 2017 [cited by applicant]
US 9740006B2 · Gao · 2017 [cited by applicant]
US 9791700B2 · Schowengerdt et al. · 2017 [cited by applicant]
US D805734S · Fisher et al. · 2017 [cited by applicant]
US 9846967B2 · Schowengerdt et al. · 2017 [cited by applicant]
US 9851563B2 · Gao et al. · 2017 [cited by applicant]
US 9857591B2 · Welch et al. · 2018 [cited by applicant]
US 9874749B2 · Bradski · 2018 [cited by applicant]
US 10191288B2 · Singer et al. · 2019 [cited by applicant]
US 10895784B2 · Oh et al. · 2021 [cited by applicant]
US 20030147112A1 · Mukawa · 2003 [cited by applicant]
US 20040184163A1 · Nishioka et al. · 2004 [cited by applicant]
US 20050232530A1 · Kekas · 2005 [cited by applicant]
US 20050253112A1 · Kelly et al. · 2005 [cited by applicant]
US 20060028436A1 · Armstrong · 2006 [cited by applicant]
US 20060126179A1 · Levola · 2006 [cited by examiner]
US 20060227283A1 · Ooi et al. · 2006 [cited by applicant]
US 20070081123A1 · Lewis · 2007 [cited by applicant]
US 20080043334A1 · Itzkovitch et al. · 2008 [cited by applicant]
US 20080169479A1 · Xu et al. · 2008 [cited by applicant]
US 20110242461A1 · Escuti et al. · 2011 [cited by applicant]
US 20120127062A1 · Bar-Zeev et al. · 2012 [cited by applicant]
US 20120162549A1 · Gao et al. · 2012 [cited by applicant]
US 20120206812A1 · Saito et al. · 2012 [cited by applicant]
US 20120242918A1 · Valyukh et al. · 2012 [cited by applicant]
US 20130082922A1 · Miller · 2013 [cited by applicant]
US 20130117377A1 · Miller · 2013 [cited by applicant]
US 20130125027A1 · Abovitz · 2013 [cited by applicant]
US 20130169909A1 · Srivastava et al. · 2013 [cited by applicant]
US 20130208234A1 · Lewis · 2013 [cited by applicant]
US 20130242262A1 · Lewis · 2013 [cited by applicant]
US 20130322810A1 · Robbins · 2013 [cited by applicant]
US 20140055740A1 · Spaulding et al. · 2014 [cited by applicant]
US 20140071539A1 · Gao · 2014 [cited by applicant]
US 20140140653A1 · Brown et al. · 2014 [cited by applicant]
US 20140140654A1 · Brown et al. · 2014 [cited by applicant]
US 20140177023A1 · Gao et al. · 2014 [cited by applicant]
US 20140218468A1 · Gao et al. · 2014 [cited by applicant]
US 20140218801A1 · Simmonds et al. · 2014 [cited by applicant]
US 20140232993A1 · Kim · 2014 [cited by applicant]
US 20140267420A1 · Schowengerdt · 2014 [cited by applicant]
US 20140293389A1 · Akutsu et al. · 2014 [cited by applicant]
US 20140306866A1 · Miller et al. · 2014 [cited by applicant]
US 20150002528A1 · Bohn et al. · 2015 [cited by applicant]
US 20150016777A1 · Abovitz et al. · 2015 [cited by applicant]
US 20150103306A1 · Kaji et al. · 2015 [cited by applicant]
US 20150168731A1 · Robbins · 2015 [cited by applicant]
US 20150178939A1 · Bradski et al. · 2015 [cited by applicant]
US 20150205126A1 · Schowengerdt · 2015 [cited by applicant]
US 20150222883A1 · Welch · 2015 [cited by applicant]
US 20150222884A1 · Cheng · 2015 [cited by applicant]
US 20150234205A1 · Schowengerdt · 2015 [cited by applicant]
US 20150235431A1 · Schowengerdt · 2015 [cited by applicant]
US 20150241705A1 · Abovitz et al. · 2015 [cited by applicant]
US 20150268415A1 · Schowengerdt et al. · 2015 [cited by applicant]
US 20150293409A1 · Usukura et al. · 2015 [cited by applicant]
US 20150302652A1 · Miller et al. · 2015 [cited by applicant]
US 20150309263A2 · Abovitz et al. · 2015 [cited by applicant]
US 20150326570A1 · Publicover et al. · 2015 [cited by applicant]
US 20150346490A1 · TeKolste et al. · 2015 [cited by applicant]
US 20150346495A1 · Welch et al. · 2015 [cited by applicant]
US 20160011419A1 · Gao · 2016 [cited by applicant]
US 20160026253A1 · Bradski et al. · 2016 [cited by applicant]
US 20160033698A1 · Escuti et al. · 2016 [cited by applicant]
US 20170007182A1 · Samec et al. · 2017 [cited by applicant]
US 20170010466A1 · Klug et al. · 2017 [cited by applicant]
US 20170010488A1 · Klug et al. · 2017 [cited by applicant]
US 20170373459A1 · Weng et al. · 2017 [cited by applicant]
US 20180046859A1 · Jarvenpaa · 2018 [cited by applicant]
US 20180113309A1 · Robbins et al. · 2018 [cited by applicant]
US 20180143485A1 · Oh · 2018 [cited by applicant]
US 20180164627A1 · Oh · 2018 [cited by applicant]
US 20180217395A1 · Lin et al. · 2018 [cited by applicant]
US 20180239147A1 · Schowengerdt · 2018 [cited by applicant]
US 20180239177A1 · Oh · 2018 [cited by applicant]
CN 104656259 · 2015 [cited by applicant]
EP 0415735 · 1991 [cited by applicant]
EP 1308767 · 2003 [cited by applicant]
EP 2887128 · 2015 [cited by applicant]
EP 3062142 · 2016 [cited by applicant]
JP 2007011057 · 2007 [cited by applicant]
JP 2015049376 · 2015 [cited by applicant]
JP 2015105990 · 2015 [cited by applicant]
JP 2015118273 · 2015 [cited by applicant]
KR 1020010067116 · 2001 [cited by applicant]
KR 1020150071612 · 2015 [cited by applicant]
KR 1020150097634 · 2015 [cited by applicant]
WO WO2010090184 · 2010 [cited by applicant]
WO WO2016194961 · 2016 [cited by applicant]
WO WO2018094079 · 2018 [cited by applicant]
WO WO2018106963 · 2018 [cited by applicant]
WO WO2018156779 · 2018 [cited by applicant]
WO WO2018156784 · 2018 [cited by applicant]
WO WO2018175343 · 2018 [cited by applicant]
WO WO2018175488 · 2018 [cited by applicant]
ARToolKit: https://web.archive.org/web/20051013062315/http://www.hitl.washington.edu:80/artoolkit/documentation/hardware.htm, archived Oct. 13, 2005, in 3 pages. [cited by applicant]
Azuma, “A Survey of Augmented Reality,” Teleoperators and Virtual Environments 6, 4 (Aug. 1997), pp. 355-385. https://web.archive.org/web/20010604100006/http://www.cs.unc.edu/˜azuma/ARpresence.pdf. [cited by applicant]
Azuma, “Predictive Tracking for Augmented Realty,” TR95-007, Department of Computer Science, UNC—Chapel Hill, NC, Feb. 1995, in 262 pages. [cited by applicant]
Bimber, et al., “Spatial Augmented Reality—Merging Real and Virtual Worlds,” 2005, in 393 pages. https://web.media.mit.edu/˜raskar/book/BimberRaskarAugmentedRealityBook.pdf. [cited by applicant]
Chigrinov, V.: Photoaligning and Photopatterning Technology: Applications in Displays and Photonics, Proceedings of SPIE, Emerging Liquid Crystal Technologies I, vol. 9769, Mar. 7, 2016, in 11 pages. [cited by applicant]
Crawford, et al.: “Liquid-crystal diffraction gratings using polarization holography alignment techniques,” Journal of Applied Physics 98, 123102, 2005. [cited by applicant]
Dierking, I.: “Chiral Liquid Crystals: Structures, Phases, Effects,” Symmetry, (Jun. 2014) 6(2): 444-472. [cited by applicant]
Escuti, M. et al., “39.4: Polarization-independent switching with high contrast from a liquid crystal polarization grating,” SID Symposium Digest, vol. 37, pp. 1443-1446, Jun. 2006, in 5 pages. [cited by applicant]
Escuti, M. et al., “Polarization-Independent LC Microdisplays Using Liquid Crystal Polarization Gratings: A Viable Solution”, ILCC presentation, Jul. 1, 2008, in 15 pages. [cited by applicant]
International Preliminary Report on Patentability for PCT Application No. PCT/US18/19257, issued Aug. 27, 2019, in 6 pages (MLEAP.057WO2). [cited by applicant]
International Preliminary Report on Patentability for PCT Application No. PCT/US2017/062063, issued May 21, 2019, in 8 pages (MLEAP.085WO). [cited by applicant]
International Preliminary Report on Patentability for PCT Application No. PCT/US2017/065182, issued Jun. 11, 2019, in 5 pages (MLEAP.099WO1). [cited by applicant]
International Preliminary Report on Patentability for PCT Application No. PCT/US2018/023425, issued Sep. 24, 2019, in 14 pages (MLEAP.109WO). [cited by applicant]
International Search Report and Written Opinion for PCT Application No. PCT/US 18123178, mailed Aug. 3, 2018, in 19 pages (MLEAP.099WO3). [cited by applicant]
International Search Report and Written Opinion for PCT Application No. PCT/US18/19250, mailed Jun. 29, 2018, in 23 pages (MLEAP.057WO1). [cited by applicant]
International Search Report and Written Opinion for PCT Application No. PCT/US18/19257, mailed Jul. 2, 2018, in 6 pages (MLEAP.057WO2). [cited by applicant]
International Search Report and Written Opinion for PCT Application No. PCT/US2017/062063, mailed Jan. 25, 2018, in 8 pages (MLEAP.085WO). [cited by applicant]
International Search Report and Written Opinion for PCT Application No. PCT/US2017/65182, mailed Apr. 6, 2018, in 5 pages (MLEAP.099WO1). [cited by applicant]
International Search Report and Written Opinion for PCT Application No. PCT/US2018/023425, mailed Jun. 22, 2018, in 14 pages (MLEAP.109WO). [cited by applicant]
Invitation to Pay Additional Fees and, Where Applicable, Protest Fee for PCT Application No. PCT/US18/19250, mailed May 2, 2018, in 3 pages (MLEAP.057WO1). [cited by applicant]
Invitation to Pay Additional Fees and, Where Applicable, Protest Fee for PCT Application No. PCT/US18/19257, mailed May 3, 2018, in 3 pages (MLEAP.057WO2). [cited by applicant]
Invitation to Pay Additional Fees and, Where Applicable, Protest Fee for PCT Application No. PCT/US18/23178, mailed Jun. 4, 2018, in 3 pages (MLEAP.099WO3). [cited by applicant]
Invitation to Pay Additional Fees and, Where Applicable, Protest Fee for PCT Application No. PCT/US2017/65182, mailed Feb. 14, 2018, in 3 pages (MLEAP.099WO1). [cited by applicant]
Jacob, “Eye Tracking in Advanced Interface Design,” Human-Computer Interaction Lab Naval Research Laboratory, Washington, D.C. / paper/ in Virtual Environments and Advanced Interface Design, ed. by W. Barfield and TA Fu… [cited by applicant]
Kim, J. et al., “Wide-angle, nonmechanical beam steering with high throughput utilizing polarization gratings,” Applied Optics, vol. 50, No. 17, Jun. 10, 2011, in 4 pages. [cited by applicant]
Komanduri, et al., “Multi-twist retarders: broadband retardation control using self-aligning reactive liquid crystal layers,” Optical Society of America, Optics Express, vol. 21, No. 1, Jan. 14, 2013, in 17 pages. [cited by applicant]
Komanduri, R. et al., “18:3: Late-News Paper: Polarization Independent Liquid Crystal Microdisplays”, SID Digest, vol. 39, No. 1, pp. 236-239, May 2008, in 4 pages. [cited by applicant]
Komanduri, R. et al., “34.4L: Late-News Paper: Polarization Independent Projection Systems using Thin Film Polymer Polarization Gratings and Standard Liquid Crystal Microdisplays”, SID Digest, vol. 40, No. 1, Jun. 2009,… [cited by applicant]
Komanduri, R. et al., “Elastic Continuum Analysis of the Liquid Crystal Polarization Grating”, Physical review. E, Statistical, nonlinear, and soft matter physics, May 25, 2007, in 8 pages. [cited by applicant]
Komanduri, R. et al., “Polarization Independent Projection Systems using Thin Film Polymer Polarization Gratings and Standard Liquid Crystal Microdisplays”, SID-Display week presentation, Jun. 3, 2009, in 12 pages. [cited by applicant]
Komanduri, R. et al., “Polarization-independent modulation for projection displays using small-period LC polarization gratings”, Journal of the Society for information display, vol. 15, No. 8, pp. 589-594, Aug. 2007, in… [cited by applicant]
Kurioz, Y. et al.: “P-128: Orientation of a Reactive Mesogen on Photosensitive Surface,” Society for Information Display (SID) Symposium Digest of Technical Papers, May 2007, in 3 pages. [cited by applicant]
Lee, et al., Negative dispersion of birefringence in two-dimensionally self-organized smectic liquid crystal and monomer thin film, Optics Letters, vol. 39, No. 17, in 5 pages, Sep. 1, 2014. [cited by applicant]
Lim, Y. et al., “Anisotropic Nano-Imprinting Technique for Fabricating a Patterned Optical Film of a Liquid Crystalline Polymer”, Journal of Nanoscience and Nanotechnology, vol. 8, pp. 4775-4778, Oct. 2008, in 4 pages. [cited by applicant]
Lub J. et al.: “Formation of Optical Films by Photo-Polymerisation of Liquid Crystalline Acrylates and Application of These Films in Liquid Crystal Display Technology,” Mol Cryst Liq Cryst., (May 2005) 429(1):77-99. [cited by applicant]
Nikolova et al., “Diffraction Efficiency and Selectivity of Polarization Holographic Recording”, Optica Acta: Int'l J Optics (1984) 31 (5):579-588. [cited by applicant]
Office Action in Chinese Appln. No. 201880020303.6, dated Nov. 10, 2021, 13 pages (with English translation). [cited by applicant]
Office Action in Japanese Appln. No. 2019-548409, dated Apr. 4, 2022, 7 pages (with English translation). [cited by applicant]
Office Action in Japanese Appln. No. 2019-548409, dated Oct. 27, 2022, 7 pages (with English translation). [cited by applicant]
Office Action in Japanese Appln. No. 2022-107069, dated May 30, 2023, 13 pages (with English translation). [cited by applicant]
Office Action in Korean Appln. No. 10-2019-7030458, dated Jun. 15, 2023, 22 pages (with English translation). [cited by applicant]
Oh C. et al.: “Achromatic Diffraction from Polarization Gratings with High Efficiency”, Opt Lett. (Oct. 2008) 33(20):2287-2289 & Erratum Opt Lett. (Dec. 2009) 34(23):3637. [cited by applicant]
Oh C., Thesis: “Broadband Polarization Gratings for Efficient Liquid Crystal Display, Beam Steering, Spectropolarimetry, and Fresnel Zone Plate”, N. C. State University, Electrical Engineering (2009) in 190 pages. [cited by applicant]
Oh, C. et al., “Numerical analysis of polarization gratings using the finite-difference time-domain method”, Physical review A, vol. 76, Oct. 12, 2007, in 8 pages. [cited by applicant]
Oh, C. et al., “Polarization-Independent Modulation using Standard LCDs and Polymer PGs”, 2008, in 6 pages. [cited by applicant]
Oh, C. et al., 16.2: Polarization-Independent Modulation Using Standard Liquid Crystal Microdisplays and Polymer Polarization Gratings, IDRC, 2008, in 4 pages. [cited by applicant]
Tanriverdi and Jacob, “Interacting With Eye Movements in Virtual Environments,” Department of Electrical Engineering and Computer Science, Tufts University, Medford, MA—paper/Proc. ACM CHI 2000 Human Factors in Computin… [cited by applicant]
Yang et al. Negative dispersion of birefringence of smectic liquid crystal-polymer composite: dependence on the constituent molecules and temperature, Optical Society of America, Optics Express 2466, vol. 23, No. 3, Feb… [cited by applicant]