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- Setala, T., et al.
(författare)
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Complete electromagnetic coherence in the space-frequency domain
- 2004
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Ingår i: Optics Letters. - 0146-9592 .- 1539-4794. ; 29:4, s. 328-330
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Tidskriftsartikel (refereegranskat)abstract
- We show that the following properties of a random electromagnetic field are equivalent: (i) the field is spatially completely coherent in the sense of the recently introduced electromagnetic degree of coherence and (ii) the electric cross-spectral density tensor factors in the two spatial variables.
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- Abdullaev, Farakhulla, et al.
(författare)
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Zeno effect and switching of solitons in nonlinear couplers
- 2011
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Ingår i: Optics Letters. - : Optical Society of America. - 0146-9592 .- 1539-4794. ; 36:23, s. 4566-4568
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Tidskriftsartikel (refereegranskat)abstract
- The Zeno effect is investigated for soliton type pulses in a nonlinear directional coupler with dissipation. The effect consists in increase of the coupler transparency with increase of the dissipative losses in one of the arms. It is shown that localized dissipation can lead to switching of solitons between the arms. Power losses accompanying the switching can be fully compensated by using a combination of dissipative and active (in particular, parity-time-symmetric) segments.
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- Albert, Jacques, et al.
(författare)
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Grating formation in pure silica-core fibers
- 2002
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Ingår i: Optics Letters. - 0146-9592 .- 1539-4794. ; 27:10, s. 809-811
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Tidskriftsartikel (refereegranskat)abstract
- Strong grating formation in pure silica-core fibers by use of 193-nm ArF-laser radiation is reported. Unsaturated refractive-index changes of Deltan similar to 0.3 X 10(-3) were observed in nontreated fiber, and changes of Deltan similar to 0.5 X 10(-3) were observed in fibers with a high hydroxyl concentration. Possible mechanisms of photosensitivity in pure silica-core fibers are discussed.
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10. |
- Alerstam, Erik, et al.
(författare)
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Single-fiber diffuse optical time-of-flight spectroscopy
- 2012
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Ingår i: Optics Letters. - 0146-9592. ; 37:14, s. 2877-2879
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Tidskriftsartikel (refereegranskat)abstract
- We demonstrate interstitial diffuse optical time-of-fight spectroscopy based on a single fiber for both light delivery and detection. Detector saturation due to the massive short-time reflection is avoided by ultrafast gating of a single photon avalanche diode. We show that the effects of scattering and absorption are separable and that absorption can be assessed independently of scattering. Measurements on calibrated liquid phantoms and subsequent Monte Carlo-based evaluation illustrate that absorption coefficients can be accurately assessed over a wide range of medically relevant optical properties. Our findings pave the way to simplified and less invasive interstitial in vivo spectroscopy. (C) 2012 Optical Society of America
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