Abstract

Light trapped within luminescent solar concentrators (LSCs) is naturally limited in angular extent by the total internal reflection critical angle, θcrit, and hence the principles of nonimaging optics can be leveraged to increase LSC concentration ratio by appropriately reshaping the edges. Here, we use rigorous ray-tracing simulations to explore the potential of this concept for realistic LSCs with compound parabolic concentrator (CPC)-tapered edges and show that, when applied to a single edge, the concentration ratio is increased by 23% while maintaining >90% of the original LSC optical efficiency. Importantly, we find that CPC-tapering all of the edges enables a significantly greater intensity enhancement up to 35% at >90% of the original optical efficiency, effectively enabling two-dimensional concentration through a cooperative, ray-recycling effect in which rays rejected by one CPC are accepted by another. These results open up a significant opportunity to improve LSC performance at virtually no added manufacturing cost by incorporating nonimaging optics into their design.

© 2012 OSA

Full Article  |  PDF Article

References

  • View by:
  • |
  • |
  • |

  1. R. Winston, Selected Papers on Nonimaging Optics (SPIE, New York, NY, 1995).
  2. R. Winston, J. C. Minano, and P. Benitez, Nonimaging Optics (Elsevier Academic, New York, NY, 2005).
  3. W. T. Welford and R. Winston, High Collection Non-Imaging Optics (Academic, New York, 1989).
  4. J. J. O'Gallagher, Nonimaging Optics in Solar Energy (Morgan & Claypool, 2008).
  5. J. Chaves, Introduction to Nonimaging Optics (CRC Press, New York, NY, 2008).
  6. M. G. Debije and P. P. C. Verbunt, “Thirty years of luminescent solar concentrator research: Solar energy for the built environment,” Adv. Energy Mater.2(1), 12–35 (2012).
    [CrossRef]
  7. A. Goetzberger, “Fluorescent Solar Energy Concentrators: Principle and Present State of Development,” in High-Efficient Low-Cost Photovoltaics: Recent Developments, V. H. R. G. A. Petrova-Koch, ed. (2009), pp. 159–176.
  8. W. G. van Sark, K. W. J. Barnham, L. H. Slooff, A. J. Chatten, A. Büchtemann, A. Meyer, S. J. McCormack, R. Koole, D. J. Farrell, R. Bose, E. E. Bende, A. R. Burgers, T. Budel, J. Quilitz, M. Kennedy, T. Meyer, C. M. Donegá, A. Meijerink, and D. Vanmaekelbergh, “Luminescent solar concentrators--a review of recent results,” Opt. Express16(26), 21773–21792 (2008).
    [CrossRef] [PubMed]
  9. E. Yablonovitch, “Thermodynamics of the fluorescent planar concentrator,” J. Opt. Soc. Am.70(11), 1362–1363 (1980).
    [CrossRef]
  10. G. Smestad, H. Ries, R. Winston, and E. Yablonovitch, “The thermodynamic limits of light concentrators,” Sol. Energy Mater.21(2-3), 99–111 (1990).
    [CrossRef]
  11. R. Winston, C. Wang, and W. Zhang, “Beating the optical Liouville theorem (How does geometrical optics know the second law of thermodynamics?),” Proc. SPIE7423, 742309, 742309-3 (2009).
    [CrossRef]
  12. A. Goetzberger and V. Wittwer, “Fluorescent planar collector-concentrators—a review,” Sol. Cells4(1), 3–23 (1981).
    [CrossRef]
  13. D. J. Farrell and M. Yoshida, “Operating regimes for second generation luminescent solar concentrators,” Prog. Photovolt. Res. Appl.20(1), 93–99 (2012).
    [CrossRef]
  14. J. Yoon, L. Li, A. V. Semichaevsky, J. H. Ryu, H. T. Johnson, R. G. Nuzzo, and J. A. Rogers, “Flexible concentrator photovoltaics based on microscale silicon solar cells embedded in luminescent waveguides,” Nat Commun.2, 343 (2011).
    [CrossRef] [PubMed]
  15. N. C. Giebink, G. P. Wiederrecht, and M. R. Wasielewski, “Resonance-shifting to circumvent reabsorption loss in luminescent solar concentrators,” Nat. Photonics5(11), 694–702 (2011).
    [CrossRef]
  16. M. J. Currie, J. K. Mapel, T. D. Heidel, S. Goffri, and M. A. Baldo, “High-efficiency organic solar concentrators for photovoltaics,” Science321(5886), 226–228 (2008).
    [CrossRef] [PubMed]
  17. A. Goetzberger and O. Schirmer, “Second-stage concentration with tapers for fluorescent solar collectors,” Appl. Phys. (Berl.)19(1), 53–58 (1979).
    [CrossRef]
  18. B. C. Rowan, L. R. Wilson, and B. S. Richards, “Advanced material concepts for luminescent solar concentrators,” IEEE J. Sel. Top. Quantum Electron.14(5), 1312–1322 (2008).
    [CrossRef]
  19. L. R. Wilson and B. S. Richards, “Measurement method for photoluminescent quantum yields of fluorescent organic dyes in polymethyl methacrylate for luminescent solar concentrators,” Appl. Opt.48(2), 212–220 (2009).
    [CrossRef] [PubMed]
  20. J. S. Batchelder, A. H. Zewail, and T. Cole, “Luminescent solar concentrators. 1: Theory of operation and techniques for performance evaluation,” Appl. Opt.18(18), 3090–3110 (1979).
    [CrossRef] [PubMed]
  21. N. C. Giebink, G. P. Wiederrecht, and M. R. Wasielewski, “Strong exciton-photon coupling with colloidal quantum dots in a high-Q bilayer microcavity,” Appl. Phys. Lett.98(8), 081103 (2011).
    [CrossRef]

2012 (2)

D. J. Farrell and M. Yoshida, “Operating regimes for second generation luminescent solar concentrators,” Prog. Photovolt. Res. Appl.20(1), 93–99 (2012).
[CrossRef]

M. G. Debije and P. P. C. Verbunt, “Thirty years of luminescent solar concentrator research: Solar energy for the built environment,” Adv. Energy Mater.2(1), 12–35 (2012).
[CrossRef]

2011 (3)

N. C. Giebink, G. P. Wiederrecht, and M. R. Wasielewski, “Strong exciton-photon coupling with colloidal quantum dots in a high-Q bilayer microcavity,” Appl. Phys. Lett.98(8), 081103 (2011).
[CrossRef]

J. Yoon, L. Li, A. V. Semichaevsky, J. H. Ryu, H. T. Johnson, R. G. Nuzzo, and J. A. Rogers, “Flexible concentrator photovoltaics based on microscale silicon solar cells embedded in luminescent waveguides,” Nat Commun.2, 343 (2011).
[CrossRef] [PubMed]

N. C. Giebink, G. P. Wiederrecht, and M. R. Wasielewski, “Resonance-shifting to circumvent reabsorption loss in luminescent solar concentrators,” Nat. Photonics5(11), 694–702 (2011).
[CrossRef]

2009 (2)

R. Winston, C. Wang, and W. Zhang, “Beating the optical Liouville theorem (How does geometrical optics know the second law of thermodynamics?),” Proc. SPIE7423, 742309, 742309-3 (2009).
[CrossRef]

L. R. Wilson and B. S. Richards, “Measurement method for photoluminescent quantum yields of fluorescent organic dyes in polymethyl methacrylate for luminescent solar concentrators,” Appl. Opt.48(2), 212–220 (2009).
[CrossRef] [PubMed]

2008 (3)

W. G. van Sark, K. W. J. Barnham, L. H. Slooff, A. J. Chatten, A. Büchtemann, A. Meyer, S. J. McCormack, R. Koole, D. J. Farrell, R. Bose, E. E. Bende, A. R. Burgers, T. Budel, J. Quilitz, M. Kennedy, T. Meyer, C. M. Donegá, A. Meijerink, and D. Vanmaekelbergh, “Luminescent solar concentrators--a review of recent results,” Opt. Express16(26), 21773–21792 (2008).
[CrossRef] [PubMed]

B. C. Rowan, L. R. Wilson, and B. S. Richards, “Advanced material concepts for luminescent solar concentrators,” IEEE J. Sel. Top. Quantum Electron.14(5), 1312–1322 (2008).
[CrossRef]

M. J. Currie, J. K. Mapel, T. D. Heidel, S. Goffri, and M. A. Baldo, “High-efficiency organic solar concentrators for photovoltaics,” Science321(5886), 226–228 (2008).
[CrossRef] [PubMed]

1990 (1)

G. Smestad, H. Ries, R. Winston, and E. Yablonovitch, “The thermodynamic limits of light concentrators,” Sol. Energy Mater.21(2-3), 99–111 (1990).
[CrossRef]

1981 (1)

A. Goetzberger and V. Wittwer, “Fluorescent planar collector-concentrators—a review,” Sol. Cells4(1), 3–23 (1981).
[CrossRef]

1980 (1)

1979 (2)

J. S. Batchelder, A. H. Zewail, and T. Cole, “Luminescent solar concentrators. 1: Theory of operation and techniques for performance evaluation,” Appl. Opt.18(18), 3090–3110 (1979).
[CrossRef] [PubMed]

A. Goetzberger and O. Schirmer, “Second-stage concentration with tapers for fluorescent solar collectors,” Appl. Phys. (Berl.)19(1), 53–58 (1979).
[CrossRef]

Baldo, M. A.

M. J. Currie, J. K. Mapel, T. D. Heidel, S. Goffri, and M. A. Baldo, “High-efficiency organic solar concentrators for photovoltaics,” Science321(5886), 226–228 (2008).
[CrossRef] [PubMed]

Barnham, K. W. J.

Batchelder, J. S.

Bende, E. E.

Bose, R.

Büchtemann, A.

Budel, T.

Burgers, A. R.

Chatten, A. J.

Cole, T.

Currie, M. J.

M. J. Currie, J. K. Mapel, T. D. Heidel, S. Goffri, and M. A. Baldo, “High-efficiency organic solar concentrators for photovoltaics,” Science321(5886), 226–228 (2008).
[CrossRef] [PubMed]

Debije, M. G.

M. G. Debije and P. P. C. Verbunt, “Thirty years of luminescent solar concentrator research: Solar energy for the built environment,” Adv. Energy Mater.2(1), 12–35 (2012).
[CrossRef]

Donegá, C. M.

Farrell, D. J.

Giebink, N. C.

N. C. Giebink, G. P. Wiederrecht, and M. R. Wasielewski, “Strong exciton-photon coupling with colloidal quantum dots in a high-Q bilayer microcavity,” Appl. Phys. Lett.98(8), 081103 (2011).
[CrossRef]

N. C. Giebink, G. P. Wiederrecht, and M. R. Wasielewski, “Resonance-shifting to circumvent reabsorption loss in luminescent solar concentrators,” Nat. Photonics5(11), 694–702 (2011).
[CrossRef]

Goetzberger, A.

A. Goetzberger and V. Wittwer, “Fluorescent planar collector-concentrators—a review,” Sol. Cells4(1), 3–23 (1981).
[CrossRef]

A. Goetzberger and O. Schirmer, “Second-stage concentration with tapers for fluorescent solar collectors,” Appl. Phys. (Berl.)19(1), 53–58 (1979).
[CrossRef]

Goffri, S.

M. J. Currie, J. K. Mapel, T. D. Heidel, S. Goffri, and M. A. Baldo, “High-efficiency organic solar concentrators for photovoltaics,” Science321(5886), 226–228 (2008).
[CrossRef] [PubMed]

Heidel, T. D.

M. J. Currie, J. K. Mapel, T. D. Heidel, S. Goffri, and M. A. Baldo, “High-efficiency organic solar concentrators for photovoltaics,” Science321(5886), 226–228 (2008).
[CrossRef] [PubMed]

Johnson, H. T.

J. Yoon, L. Li, A. V. Semichaevsky, J. H. Ryu, H. T. Johnson, R. G. Nuzzo, and J. A. Rogers, “Flexible concentrator photovoltaics based on microscale silicon solar cells embedded in luminescent waveguides,” Nat Commun.2, 343 (2011).
[CrossRef] [PubMed]

Kennedy, M.

Koole, R.

Li, L.

J. Yoon, L. Li, A. V. Semichaevsky, J. H. Ryu, H. T. Johnson, R. G. Nuzzo, and J. A. Rogers, “Flexible concentrator photovoltaics based on microscale silicon solar cells embedded in luminescent waveguides,” Nat Commun.2, 343 (2011).
[CrossRef] [PubMed]

Mapel, J. K.

M. J. Currie, J. K. Mapel, T. D. Heidel, S. Goffri, and M. A. Baldo, “High-efficiency organic solar concentrators for photovoltaics,” Science321(5886), 226–228 (2008).
[CrossRef] [PubMed]

McCormack, S. J.

Meijerink, A.

Meyer, A.

Meyer, T.

Nuzzo, R. G.

J. Yoon, L. Li, A. V. Semichaevsky, J. H. Ryu, H. T. Johnson, R. G. Nuzzo, and J. A. Rogers, “Flexible concentrator photovoltaics based on microscale silicon solar cells embedded in luminescent waveguides,” Nat Commun.2, 343 (2011).
[CrossRef] [PubMed]

Quilitz, J.

Richards, B. S.

L. R. Wilson and B. S. Richards, “Measurement method for photoluminescent quantum yields of fluorescent organic dyes in polymethyl methacrylate for luminescent solar concentrators,” Appl. Opt.48(2), 212–220 (2009).
[CrossRef] [PubMed]

B. C. Rowan, L. R. Wilson, and B. S. Richards, “Advanced material concepts for luminescent solar concentrators,” IEEE J. Sel. Top. Quantum Electron.14(5), 1312–1322 (2008).
[CrossRef]

Ries, H.

G. Smestad, H. Ries, R. Winston, and E. Yablonovitch, “The thermodynamic limits of light concentrators,” Sol. Energy Mater.21(2-3), 99–111 (1990).
[CrossRef]

Rogers, J. A.

J. Yoon, L. Li, A. V. Semichaevsky, J. H. Ryu, H. T. Johnson, R. G. Nuzzo, and J. A. Rogers, “Flexible concentrator photovoltaics based on microscale silicon solar cells embedded in luminescent waveguides,” Nat Commun.2, 343 (2011).
[CrossRef] [PubMed]

Rowan, B. C.

B. C. Rowan, L. R. Wilson, and B. S. Richards, “Advanced material concepts for luminescent solar concentrators,” IEEE J. Sel. Top. Quantum Electron.14(5), 1312–1322 (2008).
[CrossRef]

Ryu, J. H.

J. Yoon, L. Li, A. V. Semichaevsky, J. H. Ryu, H. T. Johnson, R. G. Nuzzo, and J. A. Rogers, “Flexible concentrator photovoltaics based on microscale silicon solar cells embedded in luminescent waveguides,” Nat Commun.2, 343 (2011).
[CrossRef] [PubMed]

Schirmer, O.

A. Goetzberger and O. Schirmer, “Second-stage concentration with tapers for fluorescent solar collectors,” Appl. Phys. (Berl.)19(1), 53–58 (1979).
[CrossRef]

Semichaevsky, A. V.

J. Yoon, L. Li, A. V. Semichaevsky, J. H. Ryu, H. T. Johnson, R. G. Nuzzo, and J. A. Rogers, “Flexible concentrator photovoltaics based on microscale silicon solar cells embedded in luminescent waveguides,” Nat Commun.2, 343 (2011).
[CrossRef] [PubMed]

Slooff, L. H.

Smestad, G.

G. Smestad, H. Ries, R. Winston, and E. Yablonovitch, “The thermodynamic limits of light concentrators,” Sol. Energy Mater.21(2-3), 99–111 (1990).
[CrossRef]

van Sark, W. G.

Vanmaekelbergh, D.

Verbunt, P. P. C.

M. G. Debije and P. P. C. Verbunt, “Thirty years of luminescent solar concentrator research: Solar energy for the built environment,” Adv. Energy Mater.2(1), 12–35 (2012).
[CrossRef]

Wang, C.

R. Winston, C. Wang, and W. Zhang, “Beating the optical Liouville theorem (How does geometrical optics know the second law of thermodynamics?),” Proc. SPIE7423, 742309, 742309-3 (2009).
[CrossRef]

Wasielewski, M. R.

N. C. Giebink, G. P. Wiederrecht, and M. R. Wasielewski, “Resonance-shifting to circumvent reabsorption loss in luminescent solar concentrators,” Nat. Photonics5(11), 694–702 (2011).
[CrossRef]

N. C. Giebink, G. P. Wiederrecht, and M. R. Wasielewski, “Strong exciton-photon coupling with colloidal quantum dots in a high-Q bilayer microcavity,” Appl. Phys. Lett.98(8), 081103 (2011).
[CrossRef]

Wiederrecht, G. P.

N. C. Giebink, G. P. Wiederrecht, and M. R. Wasielewski, “Resonance-shifting to circumvent reabsorption loss in luminescent solar concentrators,” Nat. Photonics5(11), 694–702 (2011).
[CrossRef]

N. C. Giebink, G. P. Wiederrecht, and M. R. Wasielewski, “Strong exciton-photon coupling with colloidal quantum dots in a high-Q bilayer microcavity,” Appl. Phys. Lett.98(8), 081103 (2011).
[CrossRef]

Wilson, L. R.

L. R. Wilson and B. S. Richards, “Measurement method for photoluminescent quantum yields of fluorescent organic dyes in polymethyl methacrylate for luminescent solar concentrators,” Appl. Opt.48(2), 212–220 (2009).
[CrossRef] [PubMed]

B. C. Rowan, L. R. Wilson, and B. S. Richards, “Advanced material concepts for luminescent solar concentrators,” IEEE J. Sel. Top. Quantum Electron.14(5), 1312–1322 (2008).
[CrossRef]

Winston, R.

R. Winston, C. Wang, and W. Zhang, “Beating the optical Liouville theorem (How does geometrical optics know the second law of thermodynamics?),” Proc. SPIE7423, 742309, 742309-3 (2009).
[CrossRef]

G. Smestad, H. Ries, R. Winston, and E. Yablonovitch, “The thermodynamic limits of light concentrators,” Sol. Energy Mater.21(2-3), 99–111 (1990).
[CrossRef]

Wittwer, V.

A. Goetzberger and V. Wittwer, “Fluorescent planar collector-concentrators—a review,” Sol. Cells4(1), 3–23 (1981).
[CrossRef]

Yablonovitch, E.

G. Smestad, H. Ries, R. Winston, and E. Yablonovitch, “The thermodynamic limits of light concentrators,” Sol. Energy Mater.21(2-3), 99–111 (1990).
[CrossRef]

E. Yablonovitch, “Thermodynamics of the fluorescent planar concentrator,” J. Opt. Soc. Am.70(11), 1362–1363 (1980).
[CrossRef]

Yoon, J.

J. Yoon, L. Li, A. V. Semichaevsky, J. H. Ryu, H. T. Johnson, R. G. Nuzzo, and J. A. Rogers, “Flexible concentrator photovoltaics based on microscale silicon solar cells embedded in luminescent waveguides,” Nat Commun.2, 343 (2011).
[CrossRef] [PubMed]

Yoshida, M.

D. J. Farrell and M. Yoshida, “Operating regimes for second generation luminescent solar concentrators,” Prog. Photovolt. Res. Appl.20(1), 93–99 (2012).
[CrossRef]

Zewail, A. H.

Zhang, W.

R. Winston, C. Wang, and W. Zhang, “Beating the optical Liouville theorem (How does geometrical optics know the second law of thermodynamics?),” Proc. SPIE7423, 742309, 742309-3 (2009).
[CrossRef]

Adv. Energy Mater. (1)

M. G. Debije and P. P. C. Verbunt, “Thirty years of luminescent solar concentrator research: Solar energy for the built environment,” Adv. Energy Mater.2(1), 12–35 (2012).
[CrossRef]

Appl. Opt. (2)

Appl. Phys. (Berl.) (1)

A. Goetzberger and O. Schirmer, “Second-stage concentration with tapers for fluorescent solar collectors,” Appl. Phys. (Berl.)19(1), 53–58 (1979).
[CrossRef]

Appl. Phys. Lett. (1)

N. C. Giebink, G. P. Wiederrecht, and M. R. Wasielewski, “Strong exciton-photon coupling with colloidal quantum dots in a high-Q bilayer microcavity,” Appl. Phys. Lett.98(8), 081103 (2011).
[CrossRef]

IEEE J. Sel. Top. Quantum Electron. (1)

B. C. Rowan, L. R. Wilson, and B. S. Richards, “Advanced material concepts for luminescent solar concentrators,” IEEE J. Sel. Top. Quantum Electron.14(5), 1312–1322 (2008).
[CrossRef]

J. Opt. Soc. Am. (1)

Nat Commun. (1)

J. Yoon, L. Li, A. V. Semichaevsky, J. H. Ryu, H. T. Johnson, R. G. Nuzzo, and J. A. Rogers, “Flexible concentrator photovoltaics based on microscale silicon solar cells embedded in luminescent waveguides,” Nat Commun.2, 343 (2011).
[CrossRef] [PubMed]

Nat. Photonics (1)

N. C. Giebink, G. P. Wiederrecht, and M. R. Wasielewski, “Resonance-shifting to circumvent reabsorption loss in luminescent solar concentrators,” Nat. Photonics5(11), 694–702 (2011).
[CrossRef]

Opt. Express (1)

Proc. SPIE (1)

R. Winston, C. Wang, and W. Zhang, “Beating the optical Liouville theorem (How does geometrical optics know the second law of thermodynamics?),” Proc. SPIE7423, 742309, 742309-3 (2009).
[CrossRef]

Prog. Photovolt. Res. Appl. (1)

D. J. Farrell and M. Yoshida, “Operating regimes for second generation luminescent solar concentrators,” Prog. Photovolt. Res. Appl.20(1), 93–99 (2012).
[CrossRef]

Science (1)

M. J. Currie, J. K. Mapel, T. D. Heidel, S. Goffri, and M. A. Baldo, “High-efficiency organic solar concentrators for photovoltaics,” Science321(5886), 226–228 (2008).
[CrossRef] [PubMed]

Sol. Cells (1)

A. Goetzberger and V. Wittwer, “Fluorescent planar collector-concentrators—a review,” Sol. Cells4(1), 3–23 (1981).
[CrossRef]

Sol. Energy Mater. (1)

G. Smestad, H. Ries, R. Winston, and E. Yablonovitch, “The thermodynamic limits of light concentrators,” Sol. Energy Mater.21(2-3), 99–111 (1990).
[CrossRef]

Other (6)

A. Goetzberger, “Fluorescent Solar Energy Concentrators: Principle and Present State of Development,” in High-Efficient Low-Cost Photovoltaics: Recent Developments, V. H. R. G. A. Petrova-Koch, ed. (2009), pp. 159–176.

R. Winston, Selected Papers on Nonimaging Optics (SPIE, New York, NY, 1995).

R. Winston, J. C. Minano, and P. Benitez, Nonimaging Optics (Elsevier Academic, New York, NY, 2005).

W. T. Welford and R. Winston, High Collection Non-Imaging Optics (Academic, New York, 1989).

J. J. O'Gallagher, Nonimaging Optics in Solar Energy (Morgan & Claypool, 2008).

J. Chaves, Introduction to Nonimaging Optics (CRC Press, New York, NY, 2008).

Cited By

OSA participates in CrossRef's Cited-By Linking service. Citing articles from OSA journals and other participating publishers are listed here.

Alert me when this article is cited.


Figures (4)

Fig. 1
Fig. 1

(a) Physical layout of a typical ray-tracing simulation for a conventional luminescent concentrator. Incident light is indicated by blue rays and luminescence by green rays. (b) Radiant intensity distribution of light reaching the edge of a conventional LSC as indicated by the side-view schematic above. Sagittal (S) and transverse (T) angles are defined according the inset of (a) for the cell highlighted in red. (c) Tapering the edge into a compound parabolic concentrator (CPC) geometry as shown in the wireframe side-view above transforms the radiant intensity distribution in (b) to fill the full 2π steradian half-space.

Fig. 2
Fig. 2

(a) Intensity increase realized for a 2 mm thick, quasi-1 dimensional CPC LSC relative to its conventional LSC counterpart calculated as a function of the acceptance angle and CPC length. As noted by the dashed green line, there is a limiting “natural” CPC length dependent upon on acceptance angle that is enforced to prevent the CPC edges from closing back in on one another at the input aperture; shorter lengths reflect a truncated CPC. The CPC input aperture is locked to the LSC edge thickness and thus the output aperture varies with CPC length. (b) Relative intensity (left-hand axis) and optical efficiency (right-hand axis) obtained for a “natural” length CPC LSC [e.g. following the green dashed line in (a)] as a function of acceptance angle. The inset illustrates the quasi-1 dimensional approximation used in these calculations, where the LSC is long and narrow with absorbing side faces to eliminate rays propagating significantly outside the sagittal plane.

Fig. 3
Fig. 3

(a) Output intensity and optical efficiency of a 100 x 100 x 2 mm LSC with natural length (dependent on θacc) CPC-tapered edges relative to its conventional LSC counterpart. Data is included for several different self-absorption ratios, SA = ∞, SA = 243, SA = 118, and SA = 56, in the order indicated by the black arrow. (b) Similar data obtained for a 100 x 100 x 5 mm LSC with CPC edges truncated to a length of 1.5 mm, showing a significant increase in both intensity and efficiency at small acceptance angle due to improved ray-recycling that results from truncation.

Fig. 4
Fig. 4

(a) Schematic showing how light rejected at the right-hand edge of a CPC LSC (green rays) is recollected at the top edge. Rays are incident from a vertically oriented (i.e. normal to the LSC faces) line source 5 mm from the midpoint of the right edge within the nominal acceptance angle of its CPC. (b) Fraction of rays collected at the right and top cells as illustrated in (a) for increasing emission azimuth in a 2 mm thick LSC with natural length CPC edges. The ϕ > 85° yellow shaded region indicates the point at which rays are incident directly on the top edge. (c) Similar data obtained for the case of a 5 mm thick LSC with truncated CPC edges.

Metrics