A self-fit optical filter includes a dual fiber collimator, a diffraction grating for spatially dispersing the input light beam into a plurality of sub-beams, a cylindrical lens for focusing each of the sub-beams at a saturable absorber which becomes saturated dependent on intensity of light, and a reflector for reflecting the sub-beams back along their optical paths. A method of filtering includes: demultiplexing an input beam into a plurality of sub-beams having distinct center wavelengths, at least partially absorbing one or more of the sub-beams by using a saturable absorber while allowing other sub-beams to pass through, substantially unattenuated, and multiplexing the sub-beams into an output optical signal.

An optical assembly includes a first grating device configured to: receive a light beam that includes an optical signal with a particular wavelength from a fiber; and change a propagation direction of the optical signal according to the particular wavelength of the optical signal. The optical assembly also includes a second grating device configured to: receive the optical signal outputted from the first grating device; change the propagation direction of the optical signal according to the particular wavelength of the optical signal; and direct the optical signal onto a grating coupler. The first grating device and the second grating device are configured to satisfy a plurality of configuration constraints.

An optical assembly includes a first grating device configured to: receive a light beam that includes an optical signal with a particular wavelength from a fiber; and change a propagation direction of the optical signal according to the particular wavelength of the optical signal. The optical assembly also includes a second grating device configured to: receive the optical signal outputted from the first grating device; change the propagation direction of the optical signal according to the particular wavelength of the optical signal; and direct the optical signal onto a grating coupler. The first grating device and the second grating device are configured to satisfy a plurality of configuration constraints.

An optical device. In some embodiments, the optical device includes a first interface; a second interface; a first plurality of waveguides, at the first interface; a second plurality of waveguides, at the second interface; and a free propagation region. A first waveguide of the first plurality of waveguides has a width at least 20% greater than a second waveguide of the first plurality of waveguides.

Embodiments of the present disclosure are directed toward an optical apparatus that includes a semiconductor layer to propagate light from at least one light source. The optical apparatus may further include a curved echelle grating with a plurality of grating teeth, the echelle grating at an outer side of the semiconductor layer. The curved echelle grating may include a plurality of grating teeth, and a grating tooth of the plurality of grating teeth may have a grating facet and a shadow facet. A shadow facet may have an angle of grating greater than 0 degrees with respect to a normal of a curve of the curved echelle grating. Other embodiments may be described and/or claimed.

Embodiments of the present disclosure are directed toward an optical apparatus that includes a semiconductor layer to propagate light from at least one light source. The optical apparatus may further include a curved echelle grating with a plurality of grating teeth, the echelle grating at an outer side of the semiconductor layer. The curved echelle grating may include a plurality of grating teeth, and a grating tooth of the plurality of grating teeth may have a grating facet and a shadow facet. A shadow facet may have an angle of grating greater than 0 degrees with respect to a normal of a curve of the curved echelle grating. Other embodiments may be described and/or claimed.

Aspects of embodiments pertain to beam combining devices for coherent and spectral beam-combining. The coherent beam combining (CBC) device may comprise a monolithic body having an input surface and an output surface. The input surface may be configured to direct a plurality of coherent entering optical beams through an optical pathway inside the monolithic body towards the output surface; and a phase mask configured for combining beams, exiting from the output surface of the monolithic body, to form a single combined output beam. The Spectral beam combining (SBC) device may include a monolithic body configured to direct the entering optical beams through a multi-diffraction optical pathway inside the monolithic body by directing the entering optical beams such as to impinge a diffractive surface thereof at least twice, for combining the entering optical beams into a single multispectral combined output optical beam. Embodiments may also include methods for cascaded beam combining, using multiple combining devices in a network configuration.

Wavelength division multiplexing (WDM) has enabled telecommunication service providers to fully exploit the transmission capacity of optical fibers. State of the art systems in long-haul networks now have aggregated capacities of terabits per second. Moreover, by providing multiple independent multi-gigabit channels, WDM technologies offer service providers with a straight forward way to build networks and expand networks to support multiple clients with different requirements. In order to reduce costs, enhance network flexibility, reduce spares, and provide re-configurability many service providers have migrated away from fixed wavelength transmitters, receivers, and transceivers, to wavelength tunable transmitters, receivers, and transceivers as well as wavelength dependent add-drop multiplexer, space switches etc. However, to meet the competing demands for improved performance, increased integration, reduced footprint, reduced power consumption, increased flexibility, re-configurability, and lower cost it is desirable to exploit/adopt monolithic optical circuit technologies, hybrid optoelectronic integration, and microelectromechanical systems (MEMS).

A self-fit optical filter includes a dual fiber collimator, a diffraction grating for spatially dispersing the input light beam into a plurality of sub-beams, a cylindrical lens for focusing each of the sub-beams at a saturable absorber which becomes saturated dependent on intensity of light, and a reflector for reflecting the sub-beams back along their optical paths. A method of filtering includes: demultiplexing an input beam into a plurality of sub-beams having distinct center wavelengths, at least partially absorbing one or more of the sub-beams by using a saturable absorber while allowing other sub-beams to pass through, substantially unattenuated, and multiplexing the sub-beams into an output optical signal.

Aspects of embodiments pertain to systems and methods for beam combining, using at least a first set of coherent beam combining (CBC) devices, each being configured to combine coherent optical beams directed thereto and to output a coherent combined output optical beam and at least one additional combining device, configured to combine multiple optical beams. Combined output optical beams, outputted by each CBC device of the first set of CBC devices, are directed towards an input surface of the at least one additional combining device, which combines the directed combined output optical beams, outputted by the first set of CBC devices, by the at least one additional combining device, outputting a single combined final output optical beam and directing thereof externally from the at least one additional combining device.