Remote control device of acousto-optic tunable filter and optical transmission system containing equalizer using acousto-optic tunable filter and optical transmission system containing optical add/drop multiplexer using acousto-optic tunable filter

A remote control device of an acousto-optic tunable filter, comprising:

• a first acousto-optic tunable filter interpolated in an upward optical transmission line, capable of controlling an output state of an upward input light signal by being supplied with a surface acoustic wave control signal through a first control port;
• a second acousto-optic tunable filter interpolated in a downward optical transmission line, capable of controlling an output state of a downward input light signal by being supplied with the surface acoustic wave control signal through a second control port;
• a third acousto-optic tunable filter interpolated in the downstream of the second acousto-optic tunable filter in the downward optical transmission line, capable of controlling an output state of the downward input light signal outputted from the second acousto-optic tunable filter by being supplied with the surface acoustic wave control signal through a third control port;
• a surface acoustic wave control signal source to generate the surface acoustic wave control signal, which is provided at a remote place from the first, second, and third acousto-optic tunable filters;
• and
• a control unit that receives an information of the surface acoustic wave control signal from the surface acoustic wave control signal source through remote transmission means, and supplies the surface acoustic wave control signal to the first, second, and third control ports of the first, second, and third acousto-optic tunable filters.

An optical transmission system containing equalizers using acousto-optic tunable filters, wherein:

• plurality of equalizers are cascaded in the optical transmission line installed between a light signal transmit terminal and a light signal receive terminal, and the equalizers are comprised of the acousto-optic tunable filters capable of controlling output states of input light signals by being supplied with surface acoustic wave control signals through control ports;
• the optical transmission system contains, at remote places from the acousto-optic tunable filters, surface acoustic wave control signal sources to generate the surface acoustic wave control signals and surface acoustic wave light control signal transmitting units that output to convert the surface acoustic wave control signals from the surface acoustic wave control signal sources into surface acoustic wave light control signals;
• and
• each of the equalizers is provided with a control unit including a receiving unit that receives the surface acoustic wave light control signal from the surface acoustic wave light control signal transmitting unit through the optical transmission line and converts the surface acoustic wave light control signal into the surface acoustic wave control signal, and a driving unit that supplies the surface acoustic wave control signal received by the receiving unit to the control port of the acousto-optic tunable filter.

An optical transmission system containing a optical add/drop multiplexer using an acousto-optic tunable filter, wherein:

• the optical add/drop multiplexer is connected through optical transmission lines between a light signal transmit terminal, a light signal receive terminal, and a branch terminal, and is comprised of the acousto-optic tunable filter capable of controlling an output state of an input light signal by being supplied with a surface acoustic wave control signal through a control port;
• the optical transmission system contains, at a remote place from the acousto-optic tunable filter, a surface acoustic wave control signal source to generate the surface acoustic wave control signal and a surface acoustic wave light control signal transmitting unit that outputs to convert the surface acoustic wave control signal from the surface acoustic wave control signal source into a surface acoustic wave light control signal;
• and
• the optical add/drop multiplexer is provided with a control unit including a receiving unit that receives the surface acoustic wave light control signal from the surface acoustic wave light control signal transmitting unit through the optical transmission line and converts the surface acoustic wave light control signal into the surface acoustic wave control signal, and a driving unit that supplies the surface acoustic wave control signal received by the receiving unit to the control port of the acousto-optic tunable filter.

A terminal for transmitting a light signal, comprising:

• a surface acoustic wave control signal source to generate a surface acoustic wave control signal used to control an acousto-optic tunable filter, which in turn controls an output state of a light signal;
• a surface acoustic wave light control signal transmitting unit to converts the surface acoustic wave control signal, which has been created by said surface acoustic wave control signal source, to a surface acoustic wave light control signal;
• and
• a wavelength multiplexer to multiplex the surface acoustic wave light control signal, which has been converted in said surface acoustic wave light control signal transmitting unit, and a light signal transmitted through a optical transmission line on which the acousto-optic tunable filter is interposed so as to produce a wavelength division multiplexed signal, which is output on the optical transmission line.