H. O. Hågenvik, M. E. Malema, and J. Skaar, “Fourier theory of linear gain media,” arXiv:1407.0187.

A. N. Bugge, S. Sauge, A. M. M. Ghazali, J. Skaar, L. Lydersen, and Vadim Makarov, “Laser damage helps the eavesdropper in quantum cryptography”, Phys. Rev. Lett. 112, 070503 (2014); arXiv:1310.8384. See also Physics Synopsis: Cyberattack by Breaking and Entering, 2014

Q. Liu, A. Lamas-Linares, C. Kurtsiefer, J. Skaar, V. Makarov and I. Gerhardt, “An universal setup for active control of a single-photon detector,” Rev. Sci. Instrum. 85, 013108 (2014); arXiv:1307.5951.

C. A. Dirdal and J. Skaar, “Superpositions of Lorentzians as the class of causal functions,” Phys. Rev. A, 88, 033834 (2013); arXiv:1307.7540.

Ø. Marøy, M. Gudmundsen, L. Lydersen, and J. Skaar , “Error estimation, error correction and verification in quantum key distribution,” IET Information Security 8, 1751-8717 (2014); arXiv:1210.6520.

G. K. Svendsen, M. W. Haakestad, and J. Skaar, “Reciprocity and the scattering matrix of waveguide modes,” Phys. Rev. A 87, 013838, 2013; arXiv: 1301.2458.

C. A. Dirdal and J. Skaar, “Negative refraction in causal media by evaluating polar paths for rational functions,” J. Opt. Soc. Am. B 30, 370–376 (2013).

G. K. Svendsen, H. Weman, and J. Skaar, “Investigations of Bragg reflectors in nanowire lasers,” J. Appl. Phys 111, 123102, 2012; arXiv: 11110767.

J. Skaar and M. W. Haakestad, “Inverse scattering of dispersive stratified structures,” J. Opt. Soc. Am. B 29, 2438-2445 (2012); arXiv:1207.7234.

J. O. Grepstad and J. Skaar, “Total internal reflection and evanescent gain,” Opt. Express 19, 21404–21418 (2011); arXiv:1009.4592.

L. Lydersen, V. Makarov, and J. Skaar, “Comment on "Resilience of gated avalanche photodiodes against bright illumination attacks in quantum cryptography",” Appl. Phys. Lett. 99, 196101 (2011); arXiv:1106.3756.

I. Gerhardt, Q. Liu, A. Lamas-Linares, J. Skaar, V. Scarani, V. Makarov, and C. Kurtsiefer, “Experimentally faking the violation of Bell's inequalities,” Phys. Rev. Lett 107, 170404 (2011); arXiv:1106.3224. See also Physics Synopsis: Eve Fools Alice and Bob, 2011.

L. Lydersen, M. K. Akhlaghi, A. H. Majedi, J. Skaar, and V. Makarov, “Controlling a superconducting nanowire single-photon detector using tailored bright illumination,” New J. Phys. 13, 113042 (2011), arXiv:1106.2396.

L. Lydersen, N. Jain, C. Wittmann, Ø. Marøy, J. Skaar, C. Marquardt, V. Makarov, and G. Leuchs, “Superlinear threshold detectors in quantum cryptography,” Phys. Rev. A 84, 032320, 2011; arXiv:1106.2119.

S. Sauge, L. Lydersen, A.Anisimov, J. Skaar, and V. Makarov, “Controlling an actively-quenched single photon detector with bright light,” Opt. Express 19, 23590 (2011); arXiv:0809.3408.

G. K. Svendsen, H. Weman, and J. Skaar, “Model for reflection and transmission matrices of nanowire end facets,” J. Appl. Phys. 109, 103101, 2011; arXiv:1012.3270.

L. Lydersen, J. Skaar, and V. Makarov, “Tailored bright illumination attack on distributed-phase-reference protocols,” J. Mod. Opt. 58, 680–685, 2011; arXiv:1012.4366.

M. P. H. Andresen, H. E. Krogstad, and J. Skaar, “Inverse scattering of 2d photonic structures by layer-stripping,” J. Opt. Soc. Am. B 28, pp. 689-696, 2011; arXiv:1102.0474.

I. Gerhardt, Q. Liu, A. Lamas-Linares, J. Skaar, C. Kurtsiefer, V. Makarov, “Full-field implementation of a perfect eavesdropper on a quantum cryptography system,” Nature Comm. 2, 349, 2011; arXiv:1011.0105.

L. Lydersen, V. Makarov, and J. Skaar, “Secure gated detection scheme for quantum cryptography,” Phys. Rev. A 83, 032306 (2011); arXiv:1101.5698.

C. Wiechers, L. Lydersen, C. Wittmann, D. Elser, J. Skaar, C. Marquardt, V. Makarov, and G. Leuchs, “After-gate attack on a quantum cryptosystem,” New J. Phys. 13, 013043 (2011), arXiv:1009.2683.

L. Lydersen, C. Wiechers, C. Wittmann, D. Elser, J. Skaar, and V. Makarov, “Avoiding the blinding attack in QKD,” Nature Photonics 4, 801 (2010); preprint arXiv:1012.0476.

L. Lydersen, C. Wiechers, C. Wittmann, D. Elser, J. Skaar, and V. Makarov, “Thermal blinding of gated detectors in quantum cryptography,” Optics Express 18, 27938-27954 (2010); arXiv:1009.2663.

Ø. Marøy, L. Lydersen, and J. Skaar, “Security of quantum key distribution with arbitrary individual imperfections,” Phys. Rev. A 82, 032337 (2010), arXiv:0903.3525.

L. Lydersen, C. Wiechers, C. Wittmann, D. Elser, J. Skaar, and V. Makarov, “Hacking commercial quantum cryptography systems by tailored bright illumination,” Nature Photonics 4, 686 - 689 (2010); presubmission version arXiv:1008.4593.

M. P. H. Andresen, A. V. Skaldebø, M. W. Haakestad, H. E. Krogstad, and J. Skaar, “Effect of gain saturation in a gain compensated perfect lens,” J. Opt. Soc. Am. B 27, 1610-1616, 2010, arXiv:1007.2486.

L. Lydersen and J. Skaar, “Security of quantum key distribution with bit and basis dependent detector flaws,” Quantum Information and Computation 10, 60-76 (2010), arXiv:0807.0767 [quant-ph].

Ø. Lind-Johansen, K. Seip, and J. Skaar, “The perfect lens on a finite bandwidth”, J. Math. Phys. 50, 012908 (2009), arXiv:0706.3054.

M. W. Haakestad and J. Skaar, “Slow and fast light in optical fibers using acoustooptic coupling between two co-propagating modes,” Opt. Express 17, 346-357 (2009).

B. Nistad and J. Skaar, “Causality and the electromagnetic properties of active media,” Phys. Rev. E 78, 036603 (2008), arXiv:0712.3132.

V. Makarov and J. Skaar, “Faked states attack using detector efficiency mismatch on SARG04, phase-time, DPSK, and Ekert protocols”, Quant. Inf. Comp. 8, 0622 (2008), arXiv:quant-ph/0702262.

B. Nistad and J. Skaar, "Simulations and realizations of active right-handed metamaterials with negative refractive index," Opt. Express 15, 10935-10946 (2007), http://www.opticsinfobase.org/abstract.cfm?URI=oe-15-17-10935.

O. H. Waagaard and J. Skaar, “Inverse scattering in multimode structures,” SIAM Journal of Applied Mathematics 68, pp. 311-333, 2007, arXiv:0707.3252.

V. Makarov, A. Anisimov, and J. Skaar, ”Effects of detector efficiency mismatch on security of quantum cryptosystems,” Phys. Rev. A 74, 022313 (2006); arXiv:quant-ph/0511032.

J. Skaar, “On resolving the refractive index and wave vector,” Opt. Lett. vol. 31, pp. 3372-3374, 2006, arXiv:physics/0607104.

J. Skaar, “Fresnel equations and the refractive index of active media,” Phys. Rev. E 73, 026605 (2006); arXiv:physics/0509112.

J. Skaar and K. Seip, “Bounds for the refractive indices of metamaterials,” J. Phys. D: Appl. Phys. 39, 1226-1229 (2006); arXiv:physics/0507001.

B. Nistad, M. W. Haakestad, and J. Skaar, “Dispersion properties of planar Bragg waveguides,” Optics Communications 265, 153-160 (2006).

K. Seip and J. Skaar, “An extremal problem related to negative refraction,” Trans. R. Norw. Soc. Sci. Lett., no. 3, pp 1-8, 2005; arXiv:math/0506620.

M. Haakestad and J. Skaar, “Causality and Kramers-Kronig relations for waveguides,” Optics Express, vol. 13, no. 24, 2005, http://www.opticsexpress.org/abstract.cfm?URI=OPEX-13-24-9922.

J. Skaar, J.C. Garcia Escartin, and H. Landro, “Quantum mechanical description of linear optics,” American Journal of Physics, vol. 72, no. 11, 1385-1391, 2004, and also in the Virtual Journal of Quantum Information, October 2004.

O. H. Waagaard and J. Skaar, “Synthesis of birefringent reflective gratings,” Journal of the Optical Society of America A, vol 21, no. 7, pp. 1207-1220, 2004; Errata, vol. 23, no. 7, pp. 1796-1796, 2006.

J. Skaar, “Iterative design of antireflection coatings based on the direct and inverse scattering transform,” Optics Communications, vol 232/1-6 pp 45-48, 2004.

K. Aksnes and J. Skaar, “Design of short fiber Bragg gratings by optimization,” Applied Optics, vol. 43, no. 11, pp. 2226-2230, 2004.

J. Skaar and O. H. Waagaard, “Design and characterization of finite length fiber gratings,” IEEE Journal of Quantum Electronics, vol. 39, no. 10, pp. 1238-1245, 2003.

J. K. Brenne and J. Skaar, “Design of grating-assisted co-directional couplers with discrete inverse-scattering algorithms,” Journal of Lightwave Technology, vol. 21, no. 1, pp. 254-263, 2003.

J. Skaar and R. Feced, “Reconstruction of gratings from noisy reflection data,” Journal of the Optical Society of America A, Volume 19, Issue 11, 2229-2237 (2002).

J. Skaar, “A numerical algorithm for extrapolation of transfer functions,” Signal Processing, vol. 83, no. 6, pp. 1213-1221, 2003.

J. Skaar, L. Wang, and T. Erdogan, “Synthesis of thick optical thin-film filters using a layer-peeling inverse scattering algorithm,” Applied Optics OT, vol. 40, no. 13, pp. 2183-2189, May 2001.

J. Skaar, “A simple method for characterization of fiber Bragg gratings,” in OSA Trends in Optics and Photonics Series (TOPS), Volume 33, Bragg Gratings, Photosensitivity, and Poling in Glass Waveguides, pp. 189-194, October 2000.

J. Skaar, “Synthesis of limited bandwidth minimum phase filters,” Inverse Problems, vol. 17, no. 2, pp. 235-246, April 2001.

J. Skaar, L. Wang, and T. Erdogan, “On the Synthesis of Fiber Bragg Gratings by Layer Peeling,” IEEE Journal of Quantum Electronics, vol. 37, no. 2, pp. 165-173, February 2001.

J. Skaar, “Synthesis of fiber Bragg gratings for use in transmission,” Journal of the Optical Society of America A, vol. 18, no. 3, pp. 557-564, March 2001.

I. Petermann, J. Skaar, B. Sahlgren, R. Stubbe and A. Friberg, “Characterization of fiber Bragg gratings by use of optical coherence-domain reflectometry,” Journal of Lightwave Technology, vol. 17, no. 11, pp. 2371-2378, Nov 1999.

J. Skaar, “Measuring the group delay of fiber Bragg gratings by use of end reflection interference”, Optics Letters, vol. 24, no. 16, pp. 1020-1022, Aug. 15, 1999.

J. Skaar and H. E. Engan, “Phase reconstruction from reflectivity in fiber Bragg gratings”, Optics Letters, vol. 24, no. 3, pp. 136-138, 1999.

D. R. Hjelme, H. Storøy, and J. Skaar, “Reconfigurable all-optical crossconnect node using synthesized fiber Bragg gratings for both demultiplexing and switching,” in OSA Trends in Optics and Photonics Series (TOPS), Volume 20, Optical Networks and Their Applications, ISBN 1-55752-545-5, Richard A. Barry, ed., pp. 280-284, September 1998.

J. Skaar and K. M. Risvik, “A genetic algorithm for the inverse problem in synthesis of fiber gratings,” Journal of Lightwave Technology, vol. 16, no. 10, pp. 1928-1932, 1998.

J. Skaar, B. Sahlgren, P.-Y. Fonjallaz, H. Storøy, and R. Stubbe, “High-reflectivity fiber-optic bandpass filter designed by use of the iterative solution to the Gel'Fand-Levitan-Marchenko equations,” Optics Letters, vol. 23, no. 12, pp. 933-935, 1998.

**SELECTED INTERNATIONAL CONFERENCE PUBLICATIONS**G. K. Svendsen, J. Skaar, H. Weman, and M.-A. Dupertuis, “Symmetries and optical transitions of hexagonal quantum dots in GaAs/AlGaAs nanowires,” ICPS 2014, Austin, Texas, USA, 2014.

A. N. Bugge, S. Sauge, A. M. M. Ghazali, J. Skaar, L. Lydersen, and V. Makarov, “Laser damage of photodiodes helps the eavesdropper” (invited), QCMC 2012, Vienna, Austria, July 30 – August 3, 2012.

J. O. Grepstad and J. Skaar, “Does evanescent gain exist?” (invited), The XXXth General Assembly and Scientific Symposium of the International Union of Radio Science, Istanbul, 2011.

Q. Liu, I. Gerhardt, V. Makarov, J. Skaar, A. Lamas-linares, V. Scarani, C. Kurtsiefer, “Implementation of an attack scheme on a practical QKD system” (invited), 14th Workshop on Quantum Information Processing, Sentosa, 2011.

L. Lydersen, V. Makarov, Ø. Marøy, J. Skaar, “Superlinear threshold detectors in quantum cryptography,” Quantum Information Computation and Processing; 2011.

L. Lydersen, J. Skaar, V. Makarov, Q. Liu, “Practical quantum hacking” (invited) Post-Quantum Security Models, Paris, 2010.

L. Lydersen, J. Skaar, V. Makarov, Q. Liu, ”Quantum cryptography and quantum hacking” (invited), govcert.nl, 2011.

L. Lydersen, J. Skaar, V. Makarov, Ø. Marøy, Q. Liu, “Quantum key distribution and quantum hacking,” (invited), Quantum Communication Workshop, 2010.

L. Lydersen, C. Wiechers, C. Wittmann, D. Elser, J. Skaar, V. Makarov, “Cracking commercial quantum cryptography,” International Conference on Quantum Information and Computation, 2010.

L. Lydersen, C. Wiechers, C. Wittmann, D. Elser, J. Skaar, V. Makarov, “Hacking commercial quantum cryptography systems by tailored bright illumination, “ UQCC2010 - Updating Quantum Cryptography and Communications, 2010.

V. Makarov, L. Lydersen, Q. Liu, C. Wiechers, C. Wittmann, D. Elser, I. Gerhardt, S. Sauge, J. Skaar, A. Lamas-Linares, C. Kurtsiefer, ”Perfect eavesdropping: 100% key, 0% QBER” (invited), Tropical QKD workshop, Waterloo, 2010.

C. Wiechers, L. Lydersen, N. Jain, C. Wittmann, D. Elser, V. Makarov, C. Marquardt, J. Lucio, J. Skaar, G. Leuchs, “Improving quantum key distribution systems by quantum hacking tests,” Quantum Optics V, Cozumel, 2010.

J. Skaar, “Causality and its implications for passive and active media,” (invited) , URSI International Symposium on Electromagnetic Theory, EMTS 2010, Berlin, 2010; arXiv:1008.2874 [physics.optics].

Ø. Marøy, L. Lydersen, and J. Skaar, “Security of Quantum Key Distribution with Imperfect Equipment”. 18th International Laser Physics Workshop, Barcelona, 2009.

G. K. Svendsen, M.-A Dupertuis, H. Weman, and J. Skaar, “Modeling of optical and electronic properties of semiconductor nanowires”, Northern optics 2009.

L. Lydersen and J. Skaar, “Security of quantum key distribution with bit and basis dependent detector flaws,” Information Security in a Quantum World, Waterloo, Canada, August 2008.

L. Lydersen and J. Skaar, “Security of quantum key distribution with bit and basis dependent detector flaws”, SECOQC, Vienna, 2008.

G. K. Svendsen, H. Weman, and J. Skaar, “Modeling of reflection properties of nanowire lasers,” 17th International Laser Physics Workshop, Trondheim, June/July 2008.

V. Makarov, Andrey Anisimov, and J. Skaar, “Faked states attack exploiting detector efficiency mismatch on BB84, phase-time, DPSK, and Ekert protocols,” XI International Conference on Quantum Optics in Minsk, Belarus, May, 2006.

B. Nistad and J. Skaar, “Lumped circuit model for an active right-handed medium with negative refractive index,” Photonic Metamaterials: From Random to Periodic (OSA Topical meeting), Grand Island, The Bahamas, June 2006.

M. W. Haakestad and J. Skaar, “Causality and Kramers-Kronig relations for waveguides,” The Conference on Lasers and Electro-Optics/International Quantum Electronics Conference, Long Beach, California, May 2006.

B. Nistad and J. Skaar, “Active right-handed metamaterials with negative refractive index,” Northern Optics, Bergen, 2006.

J. Skaar, “Inverse scattering for one-dimensional periodic optical structures and application to design and characterization,” (invited), in Bragg Gratings, Photosensitivity, and Poling in Glass Waveguides, Sydney, July 2005. See www.iet.ntnu.no/~jskaar/bragg.zip.

B. Nistad and J. Skaar, “Bragg waveguides and gratings with negative index materials,” in Bragg Gratings, Photosensitivity, and Poling in Glass Waveguides, Sydney, July 2005.

G. Heiberg, J. Skaar, M. Fokine, and L. Arnberg, “A new method for temperature measurement in solidifying aluminium alloys by use of optical fiber Bragg grating sensors,” in the CastExpo and AFS Congress, American Foundry Society, May 2002.

F. Carlsson, P.-Y. Fonjallaz, M. Popov, J. Skaar and S. Helmfrid, “Design and fabrication of superimposed fibre Bragg gratings: models, methods, and limitations,” in the Summer School on Photosensitivity (POWAG' 2002), St. Petersburg, June 2002.

J. Skaar, “Grating reconstruction from noisy reflection data,” in Bragg Gratings, Photosensitivity, and Poling in Glass Waveguides, Stresa, Italy, July 2001.

T. Kjerre, Ø. Farsund, J. Skaar, K. Pran, G. B. Havsgård, and G. Wang, “Experimental technique for strain gradient measurement with embedded fiber Bragg gratings by use of a tunable external cavity laser,” in 14th International Conference on Optical Fiber Sensors (OFS 2000).

J. Skaar, “Characterization of fiber Bragg gratings by use of end reflection interference,” in Bragg Gratings, Photosensitivity, and Poling in Glass Waveguides, OSA Technical Digest (Optical Society of America, Washington DC, 1999), pp. 242-244.

J. Skaar and H. E. Engan, “Distributed intragrating sensing using phase retrieval,” in 13th International Conference on Optical Fiber Sensors (OFS 1999), Kuongju, S. Korea, B. U. Kim and K. Hotate, Editors, Proceedings of SPIE Vol. 3746, 588-591 (1999) S. Korea, April 1999.

I. Petermann, B. Sahlgren, J. Skaar, P.-Y. Fonjallaz, and R. Stubbe, “Phase distribution measurement of fibre Bragg gratings with white light interferometry,” European Conference on Optical Communications (ECOC), Madrid, Spain, September 1998.

P.-Y. Fonjallaz, J. Skaar, B. Sahlgren, H. Storøy and R. Stubbe, “Optimised fibre Bragg grating filters for telecommunications”, Summer School on Photosensitivity in Optical Waveguides and Glasses, Switzerland, July 1998

D. R. Hjelme, H. Storøy, and J. Skaar, “Reconfigurable all-fiber all-optical crossconnect node using synthesized fiber Bragg gratings for both demultiplexing and switching,” Optical Fiber Communication Conference (OFC), San Jose, California, February 1998.

J. Skaar and K. M Risvik, “A genetic algorithm for the inverse problem in synthesis of fiber gratings,” European Workshop on Optical Fibre Sensors, Scotland, July 1998.

**POPULAR SCIENCE, LECTURE NOTES, AND BOOK CHAPTERS****Media contributions in the Cristin database.**J. Skaar, A. Løland og T. Rolén, “Hvor fort går du på ski?”. Finnes i populærversjon i Gemini, skrevet av Steinar Brandslet, 2013.

L. Lydersen og J. Skaar, “Kvantekryptografi”, Fra fysikkens verden, nr. 1, s. 10-14, 2013.

J. Skaar, “Fiber Bragg gratings: Analysis and synthesis techniques,” in “Fiber Bragg Grating Sensors: Recent Advancements, Industrial Applications and Market Exploitation,” pp. 35-52, eISBN: 978-1-60805-084-0, Andrea Cusano, Antonello Cutolo, Jacques Albert, Editors, Bentham Science Publishers, 2010. A similar document can be found here.

J. Skaar, “Negative refraction: a tutorial,” NTNU, 2010; arXiv:1008.3223

J. Skaar, “Elektromagnetisme,” NTNU, 2011.

J. Skaar, “Musikkens fysikk,” NTNU, 2010.

J. Skaar, “Vektoranalyse,” NTNU, 2010.

J. Skaar, “Maxwells likninger,” NTNU, 2010.

J. Skaar, “Elektronikksett”, for barn fra 10 år, 2010.

**PHD THESIS**J. Skaar, “Synthesis and characterization of fiber Bragg gratings,” PhD dissertation, The Norwegian University of Science and Technology, November 2000. Some corrections can be found here. Transfer matrix and layer-peeling matlab functions can be downloaded here.

**JOURNAL PUBLICATIONS**