Spatially addressable surface emission sum frequency device

A monolithic integrated circuit comprising:

• a multilayer waveguide wherein each adjacent layer of the multilayer waveguide has different linear and non-linear optical properties;
• and
• a separate confined single quantum well heterostructure embedded in the multilayer waveguide for providing gain of an optical signal.

In a non-linear waveguide having an integrated tunable laser for generating a coherent light signal, a method of propagating an optical signal in a plurality of directions in space comprising the steps of:

• a) directing an other contra-propagating optical signal into a non-linear waveguide means for generating an output optical signal, the direction of the output optical signal being determined by the frequency difference between the coherent light-signal and the other optical signal;
• and,
• b) varying the frequency coherent light-signal.