An optical module that implements an MMI device including an optical hybrid primarily made of semiconductor material is disclosed. The MMI device, which has a rectangular plane shape and includes multi-mode couplers, is mounted on a carrier. The carrier provides a step extending in a whole lateral width of a top surface thereof, where the step makes a gap against the MMI device in an area where the MMI couplers are formed.

An optical module including a circuit board, a circuit adapter board disposed on and electrically connected to the circuit board, a silicon optical chip disposed on and electrically connected to the circuit adapter board, an optical fiber socket optically connected to the silicon optical chip through a first optical fiber ribbon, and a light source disposed on and electrically connected to the circuit board and optically connected to the silicon optical chip through a second optical fiber ribbon; wherein a thermal expansion coefficient of the circuit adapter board is lower than that of the circuit board, the silicon optical chip is provided with optical waveguide end facet on a side thereof configured to be butted with the first optical fiber ribbon and the second optical fiber ribbon, and the circuit adapter board has a notch on a side thereof proximate to the optical waveguide end facets.

An arrayed waveguide grating device comprises a substrate, an arrayed waveguide grating chip, and a pivoting member. The substrate comprises a first plate portion and a second plate portion which are separated; the first plate portion and the second plate portion are made of the same material; the arrayed waveguide grating chip comprises an input planar waveguide; the input planar waveguide comprises a first part disposed at the first plate portion of the substrate and a second part disposed at the second plate portion of the substrate; and the pivoting member is made of a material different from that of the substrate and connects the first plate portion and the second plate portion of the substrate, so that the first plate portion and the second plate portion are movable relative to each other.

A thermal compensator, for use in connection with arrayed waveguide grating (AWG) modules which are, in turn, utilized in conjunction with wavelength multiplexing and de-multiplexing within optical networks, is disclosed. The thermal compensator comprises a bow-shaped frame member and a central bar member. The bow-shaped frame member is characterized by a higher coefficient of thermal expansion than that of the central bar member such that the bow-shaped frame member can expand and contract at variable rates compared to that of the central bar member under certain temperature conditions. The bow-shaped frame member is adapted to be attached to a movable section of an athermal arrayed waveguide grating (AAWG) module such that the expansion and contraction movements of the bow-shaped member influence the movement of a movable section of the AAWG module in order to maintain the proper focus of the AAWG module across disparate temperature conditions.