Abstract: Methods for adjusting dither amplitude for MEMS mirrors in optical switches and optical switches employing such a method are disclosed. A dither amplitude of one or more MEMS mirrors may be adjusted in an optical switch having an input port, and an array of one or more MEMS mirrors that can be selectively optically coupled to one or more of N?3 optical input/output (I/O) ports. The MEMS mirrors are aligned mirrors to achieve nominal peak coupling at each of the N collimators. Digital-to-analog (DAC) settings for positioning mirrors in an open control loop as a function of the selected collimator are stored to a non-volatile memory. The DAC settings are used to determine a dither amplitude DITHER(x) for one of the MEMS mirrors positioned to couple optical signals to an output port at a position x.

Abstract: Effects of diffraction of a spectral beam from an edge of the micromirrors are reduced in order to optimize the passband in a wavelength selective switch. The effects of diffraction on the pass band may be reduced by using rotation of the micromirror about both the attenuation axis and the switching axis to achieve the desired level of attenuation. Peak coupling can be attained by dithering the micromirror about a dither axis that is tangent to a contour of constant attenuation using simultaneous rotation about the switching and attenuation axes. A power level of a spectral channel may be attenuated by rotating the channel micromirror with respect to an effective attenuation axis that is non-orthogonal to the dither axis through a combination of rotations about the switching axis and the attenuation axis.

Abstract: Effects of diffraction of a spectral beam from an edge of the micromirrors are reduced in order to optimize the passband in a wavelength selective switch. The effects of diffraction on the pass band may be reduced by appropriate modification of the edges of the micromirrors, by modification of the input and/or output ports to allow for attenuation by rotation of the micromirror about the switching axis, by using rotation of the micromirror about both the attenuation axis and the switching axis to achieve the desired level of attenuation, by inserting an aperture at a focal plane or external to the device to reduce the magnitude of the micromirror edge diffraction transmitted to any or all output ports, or by appropriate filtering of angular frequencies with a diffraction grating used to separate a multi-channel optical signal into constituent spectral beams.

Abstract: Effects of diffraction of a spectral beam from an edge of the micromirrors are reduced in order to optimize the passband in a wavelength selective switch. The effects of diffraction on the pass band may be reduced by using rotation of the micromirror about both the attenuation axis and the switching axis to achieve the desired level of attenuation. Peak coupling can be attained by dithering the micromirror about an axis tangent to a contour of constant attenuation using simultaneous rotation about the switching and attenuation axes.