HYBRID POLARIZATION-MULTIPLEXED COHERENT PIC TRANSMITTERS AND RECEIVERS

Consistent with the present disclosure, active devices, such as lasers, optical amplifiers, and photodiodes, are integrated on a first substrate, and other optical devices, such as passive devices including polarization rotators and polarization beam combiners, are provided on a second substrate. An array of lenses is provided between the two substrates to provide a low loss optical connection from the first substrate to the second substrate. In addition, the orientation or position of the lenses can be readily controlled with Microelectromechnical System (MEMS) actuators so that the light can be directed precisely to a desired optical element, such as a waveguide. Consistent with a further aspect of the present disclosure, the lenses may be controlled to be misaligned by varying degrees in order to control the amount of light that is supplied from one substrate to another. Accordingly, the lenses may act as variable optical attenuators to provide uniform optical power levels, for example, or any desired power distribution.