A light detection module includes: a TO base and a TO cap; wherein the TO base is fixedly provided thereon with a first optical sensor, a support frame and a support base; the support frame is fixedly provided thereon with a beam splitter, and the beam splitter and the first optical sensor are at an angle of 45 degrees; an upper surface of the support base is fixedly provided thereon with an optical resonator and a second optical sensor, the optical resonator is located between the beam splitter and the second optical sensor, and the optical resonator, the second optical sensor and the beam splitter are on a straight line parallel to a surface of the TO base; and the TO cap is provided thereon with an opening, and the opening, the first optical sensor and the beam splitter are on a straight line perpendicular to the surface of the TO base.

An optoelectronic switch for switching a signal from an input device to an output device includes a plurality of switch modules, each connected or connectable to an optical interconnecting region, wherein: each switch module is configured to output a WDM output signal to the optical interconnecting region, and the optoelectronic switch further includes one or more MZI routers, each configured to direct the WDM output signal from its source switch module towards its destination switch module, wherein the one or more MZI routers are located either on each of the switch modules, or in the interconnecting region.

A fast optical switch can be fabricated/constructed, when a vanadium dioxide (VO.sub.2) and a two-dimensional (2-D) material is activated by either an electrical pulse (a voltage pulse or a current pulse) or a light pulse just to induce an insulator-to-metal phase transition (IMT) in vanadium dioxide. The applications of such a fast optical switch for an on-demand optical add-drop subsystem, integrating with (a) a light slowing/light stopping component (based on metamaterials and/or nanoplasmonic structures) and (b) with or without a wavelength converter are also described.

A fast optical switch can be fabricated/constructed, when a vanadium dioxide (VO.sub.2) and a two-dimensional (2-D) material is activated by either an electrical pulse (a voltage pulse or a current pulse) or a light pulse just to induce an insulator-to-metal phase transition (IMT) in vanadium dioxide. The applications of such a fast optical switch for an on-demand optical add-drop subsystem, integrating with or without a wavelength converter are also described.

A light detection module includes: a TO base and a TO cap; wherein the TO base is fixedly provided thereon with a first optical sensor, a support frame and a support base; the support frame is fixedly provided thereon with a beam splitter, and the beam splitter and the first optical sensor are at an angle of 45 degrees; an upper surface of the support base is fixedly provided thereon with an optical resonator and a second optical sensor, the optical resonator is located between the beam splitter and the second optical sensor, and the optical resonator, the second optical sensor and the beam splitter are on a straight line parallel to a surface of the TO base; and the TO cap is provided thereon with an opening, and the opening, the first optical sensor and the beam splitter are on a straight line perpendicular to the surface of the TO base.

[Problem] To provide an optical packet buffer control device, without making device construction large in scale, that is capable of dynamically responding to traffic and suppressing power consumption. [Solution] An optical delay line and electronic buffer merged-type optical packet buffer control device having N number of input terminals (11), an optical packet information acquisition unit (13), a plurality of switches (15), a plurality of delay lines (17), an electronic buffer (19), an output terminal (21), and a buffer control unit (23), wherein the buffer control unit (23) receives packet information and analyzes packet traffic, and exerts control so as not to use the electronic buffer (19) when the packet traffic is equal to or less than a first threshold, or receives information pertaining to the use state of the delay lines and exerts control so as not to use the electronic buffer (19) when the use rate of the delay lines (the percentage of the number of used delay lines relative to the total number of delay lines) is equal to or less than a first threshold pertaining to the use rate. This device can expand capacity by utilizing the electronic buffer at the time of congestion, and can dynamically respond to changes in traffic.

A wavelength cross connect device includes: a WXC unit including input-side WSSes and Output-side WSSes; and a wavelength band switching unit. Of wavelength multiplexed signal beams N-split by each input-side WSS, wavelength multiplexed signal beams in which optical signals for which wavelength band conversion is not necessary are multiplexed are input to the output-side WSSes. The wavelength band switching unit performs wavelength band conversion on, of the N-split wavelength multiplexed signal beams, a selected wavelength multiplexed signal beam in which optical signals for which wavelength band conversion is necessary are multiplexed, to generate a wavelength-band-converted wavelength multiplexed signal beam in which the wavelength bands of optical signals of distinct wavelength bands multiplexed in the wavelength multiplexed signal beam have been converted, and outputs the wavelength-band-converted wavelength multiplexed signal beam to one of the output-side WSSes so as to be rerouted.

A frequency conversion device includes: an optical convertor configured to convert a source modulated light into an unmodulated light; and a frequency convertor configured to use the unmodulated light converted by the optical convertor as a reference light and convert the source modulated light into a modulated light that has a desirable frequency.

A fast optical switch can be fabricated/constructed, when vanadium dioxide (VO.sub.2) ultra thin-film or vanadium dioxide (VO.sub.2)/two-dimensional (2-D) material or a cluster of vanadium dioxide particles (less than 0.5 microns in diameter) embedded in an ultra thin-film of a polymeric material or in a mesh of metal nanowires is activated by either an electrical pulse (a voltage pulse or a current pulse) or a light pulse just to induce rapid insulator-to-metal phase transition (IMT) in vanadium dioxide ultra thin-film or vanadium dioxide particles embedded in an ultra thin-film of a polymeric material or in a mesh of metal nanowires. The applications of such a fast optical switch for an on-Demand optical add-drop subsystem, integrating with or without a wavelength converter are also described.

A wavelength cross connect device includes: a wavelength band switching unit configured to receive wavelength multiplexed signal beams each having been transmitted in multiple bands in optical transmission lines each including one or more optical fibers, the wavelength multiplexed signal beams each including multiplexed optical signals of distinct wavelength bands, perform wavelength band conversion on each of the wavelength multiplexed signal beams so as to convert the wavelength bands of the optical signals multiplexed in the wavelength multiplexed signal beam, and output the converted wavelength multiplexed signal beams; and a WXC unit including input-side WSSes that respectively split and output the wavelength multiplexed signal beams output from the wavelength band switching unit, and output-side WSSes mesh-connected to the input-side WSSes. The WXC unit inputs the split wavelength multiplexed signal beams to the output-side WSSes while performing rerouting and outputs the rerouted wavelength multiplexed signal beams to output transmission lines.