1993/04/21 by G. Barton, K. Scharnhorst · 7 citations
Engineering · Physics and Astronomy · Mathematics · #Photonic and Optical Devices #Laser-Matter Interactions and Applications #Advanced Fiber Laser Technologies #Physics #Omega #Brillouin zone #Infinity #Dispersion (optics) #Order (exchange) #Optics #Zero (linguistics) #Dispersion relation #Refractive index #Quantum mechanics #Mathematical analysis #Mathematics
paper · doi:10.1088/0305-4470/26/8/024
openalex publication_date 1993/04/21 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/04
Because it is scattered by the zero-point oscillations of the quantized fields, light of frequency omega travelling normally to two parallel mirrors experiences the vacuum between them as a dispersive medium with refractive index n( omega ). An earlier low-frequency result that n(0)<1 is combined with the Kramers-Kronig dispersion relation for n and with the classic Sommerfeld-Brillouin argument to show (under certain physically reasonable assumptions) that either n( infinity )<1, in which case the signal velocity c/n( infinity ) exceeds c; or that the imaginary part of n is negative at least for some ranges of frequency, in which case the vacuum between the mirrors fails to respond to a light probe like a normal passive medium. Further, the optical theorem suggests that n exhibits no dispersion to order e 4 , i.e. that n( infinity )=n(0) up to corrections of order e 6 at most.