Patent ID: 7203401

Claim:
A method for forming an optical apparatus, comprising: forming a planar optical waveguide substantially confining in at least one transverse spatial dimension optical signals propagating therein; forming at least one set of locking diffractive elements in or on the planar optical waveguide; forming means for routing an optical signal corresponding to at least one said set of locking diffractive elements; and positioning a laser corresponding to at least one said set of locking diffractive elements so as to launch a corresponding laser optical signal into the planar optical waveguide so that the corresponding laser optical signal is successively incident on the diffractive elements of the corresponding locking diffractive element set, wherein: each locking diffractive element set routes within the planar optical waveguide a fraction of the corresponding laser optical signal back to the corresponding laser, with a corresponding locking transfer function, as a corresponding locking optical feedback signal, thereby substantially restricting the corresponding laser optical signal to a corresponding laser operating wavelength range determined at least in part by the corresponding locking transfer function of the corresponding locking diffractive element set; and each corresponding routing means routes within the planar optical waveguide, between the corresponding laser and a corresponding output optical port with a corresponding routing transfer function, at least a portion of that fraction of the corresponding laser optical signal that is transmitted by the corresponding locking diffractive element set.