Simultaneous higher-order Hong and Mandel's squeezing of both quadrature components in orthogonal even coherent state

We study higher-order Hong and Mandel's squeezing of both quadrature components for an arbitrary 2nth order (n not equal 1) considering the most general Hermitian quadrature operator, X-theta =X-1 cos theta +X-2 sin theta, in the orthogonal even coherent state defined by vertical bar psi > = K[vertical bar alpha, +) + vertical bar i alpha, +)]. Here vertical bar alpha, +> = K'[vertical bar alpha > + vertical bar -alpha >] an and vertical bar i alpha, +) = K ''[vertical bar i alpha > + vertical bar - i alpha)] are even coherent states, la) is coherent state, alpha = Ae(i theta)alpha, K = cosh vertical bar alpha vertical bar(2)/2[cosh vertical bar alpha vertical bar(2) + cos vertical bar alpha vertical bar(2)], and K' = K '' = [2(1 + e-2 vertical bar alpha vertical bar(2))](-1/2). We find that maximum simultaneous 2nth-order Hong and Mandel's squeezing of both quadrature components X-theta and X theta+pi/2 in the state vertical bar psi > occurs at theta = theta(alpha) +/- (pi/4) for an arbitrary order 2n (n not equal 1). We conclude that any large amount of higher-order squeezing in the state vertical bar psi > can be obtained by choosing suitably a large 2n but in this case minimum values of the 2nth-order moments become less close to the corresponding best minimum values explored numerically so far. Variations of 2nth order squeezing for n = 2,3 and 4, i.e., for fourth-order, sixth-order and eighth-order squeezing with different parameters have also been discussed. (C) 2012 Elsevier GmbH. All rights reserved.