Transverse effects in optical cavities and nonlinear optics

Jack Boyce

L. Lopez, Sylvain Gigan, Nicolas Treps +3 more

Up to now, transverse quantum effects (usually labeled as ``quantum imaging'' effects) which are generated by nonlinear devices inserted in resonant optical cavities have been calculated using the ``thin-crystal approximation,'' i.e., taking into account the effect of diffraction only inside the empty part of the cavity, and neglecting its effect in the nonlinear propagation inside the nonlinear crystal. We introduce in the present paper a theoretical method which is not restricted by this approximation. It allows us in particular to treat configurations closer to the actual experimental ones, where the crystal length is comparable to the Rayleigh length of the cavity mode. We use this method in the case of the confocal optical parametric oscillator, where the thin-crystal approximation predicts perfect squeezing on any area of the transverse plane, whatever its size and shape. We find that there exists in this case a ``coherence length'' which gives the minimum size of a detector on which perfect squeezing can be observed, and which gives therefore a limit to the improvement of optical resolution that can be obtained using such devices.

W. J. Firth

Andrew J. Scroggie, Gian‐Luca Oppo, John Jeffers +1 more

We show that plane-mirror optical cavities (linear and nonlinear) can convert spatially phase (amplitude) modulated input beams into amplitude (phase) modulated outputs. The effect occurs for only one sign of the effective cavity detuning.

Steven C. Hill

Lopez, Laurent, Sylvain Gigan, Nicolas Treps +3 more

Up to now, transverse quantum effects (usually labelled as "quantum imaging" effects) which are generated by nonlinear devices inserted in resonant optical cavities have been calculated using the "thin crystal approximation", i.e. taking into account the effect of diffraction only inside the empty part of the cavity, and neglecting its effect in the nonlinear propagation inside the nonlinear crystal. We introduce in the present paper a theoretical method which is not restricted by this approximation. It allows us in particular to treat configurations closer to the actual experimental ones, where the crystal length is comparable to the Rayleigh length of the cavity mode. We use this method in the case of the confocal OPO, where the thin crystal approximation predicts perfect squeezing on any area of the transverse plane, whatever its size and shape. We find that there exists in this case a "coherence length" which gives the minimum size of a detector on which perfect squeezing can be observed, and which gives therefore a limit to the improvement of optical resolution that can be obtained using such devices.