An optical signal isolation device comprising a common port, an isolated diagnostic port, an integrated circulator comprising an input circulator fiber, an output circulator fiber, and a fiber-to-fiber optical coupler configured to couple an isolated optical signal propagating along the input circulator fiber to the output circulator fiber for propagation along the output circulator fiber, a multi-fiber alignment body that secures at least portions of each of the multi-signal fiber, the isolated diagnostic signal fiber, the input circulator fiber, and the output circulator fiber, and a wavelength-selective optical assembly including an optical signal filter, fiber-to-filter focusing optics, and a communications signal reflector. The integrated circulator and the wavelength selective optical assembly are configured such that the communications component is retro-reflected back to the common port and the diagnostic component is passes out of the isolated diagnostic port.

An integrated cavity-enhanced photodetector for visible photonics is provided. The photodetector includes a waveguide, an absorption layer, a set of metal contacts and a phase shifter. The photodetector can be used for visible photonics with multi-material integration flow and low loss.

Embodiments disclosed herein include optoelectronic systems and methods of forming such systems. In an embodiment, an optoelectronic system comprises a first substrate, a second substrate over the first substrate, a micro-ring resonator (MRR) over the second substrate, a heater integrated into the MRR, a cladding over the MRR, an opening through the first substrate and the second substrate to expose a bottom surface of the MRR, and a base spanning across the opening.