Baynes, F.Luiten, A.Tobar, M.2016-05-272016-05-272011Physical Review D: Particles, Fields, Gravitation and Cosmology, 2011; 84(8):081101-1-081101-51550-79981550-2368http://hdl.handle.net/2440/99161We present the first experimental test of Lorentz invariance using the frequency difference between counter-propagating modes in an asymmetric odd-parity optical resonator. This type of test is ∼104 more sensitive to odd-parity and isotropic (scalar) violations of Lorentz invariance than equivalent conventional even-parity experiments due to the asymmetry of the optical resonator. The disadvantages of odd-parity resonators have been negated by the use of counter-propagating modes, delivering a high level of immunity to environmental fluctuations. With a nonrotating experiment our result limits the isotropic Lorentz violating parameter κ˜tr to 3.4±6.2×10−9, the best reported constraint from direct measurements. Using this technique the bounds on odd-parity and scalar violations of Lorentz invariance can be improved by many orders of magnitude.en© 2011 American Physical SocietyJournal article003000846510.1103/PhysRevD.84.0811010002965265000012-s2.0-8065512812175574Luiten, A. [0000-0001-5284-7244]