Pump directed optical switching element
First Claim
1. An optical switch comprising:
- a signal path having an input waveguide and an output waveguide for guiding an optical signal;
pump-dependent attenuator means, optically connected to said signal path for passing said optical signal from said input waveguide to said output waveguide in response to receiving optical energy at a pumping wavelength and for attenuating said optical signal in an absence of receiving said optical energy at said pumping wavelength;
pump means for continuously generating optical energy for introduction to said signal path, said pump means having a condition in which optical energy is generated at said pumping wavelength; and
pump-energy controller means for controlling one of a wavelength of optical energy generated by said pump means and transmission characteristics of a path from said pump means to said pump-dependent attenuator means, said transmission characteristics being specific to said optical energy at said pumping wavelength.
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Accused Products
Abstract
An optical switch includes a pump source, a pump director, and a pump-dependent attenuator. The pump-dependent attenuator passes optical signals when it is supplied with pump energy at a pumping wavelength and attenuates optical signals when it is not supplied with pump energy. The pump source generates pump energy for the pump-dependent attenuator, and the pump director optically manipulates the delivery of pump energy to the pump-dependent attenuator. In a preferred embodiment, the pump-dependent attenuator is an erbium-doped fiber (EDF), the pump source is a laser diode, and the pump director is a tunable fiber Bragg grating (FBG). The EDF is located along an optical signal transmission path between an input waveguide and an output waveguide. The tunable FBG is located along a transmission path between the laser diode and the EDF. To operate the switch, pump energy at a pumping wavelength is generated by the laser diode and transmitted toward the tunable FBG. To turn on the switch, the FBG is tuned off of the pumping wavelength of the EDF, thereby passing pump energy to the EDF, and to turn off the switch, the FBG is tuned onto the pumping wavelength of the EDF, thereby blocking pump energy to the EDF. An adjustable bandpass filter may also be used as the pump director. The optical switch can also be applied to various optical systems, such as a 1×N switch, add/drop multiplexers, broadcast/multicast switches, and wavelength-selectable lasers.
36 Citations
20 Claims
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1. An optical switch comprising:
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a signal path having an input waveguide and an output waveguide for guiding an optical signal; pump-dependent attenuator means, optically connected to said signal path for passing said optical signal from said input waveguide to said output waveguide in response to receiving optical energy at a pumping wavelength and for attenuating said optical signal in an absence of receiving said optical energy at said pumping wavelength; pump means for continuously generating optical energy for introduction to said signal path, said pump means having a condition in which optical energy is generated at said pumping wavelength; and pump-energy controller means for controlling one of a wavelength of optical energy generated by said pump means and transmission characteristics of a path from said pump means to said pump-dependent attenuator means, said transmission characteristics being specific to said optical energy at said pumping wavelength. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8)
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9. A method of controlling the transmission of optical signals input into an optical system having a wavelength-dependent optical attenuator that is optically connected to an input waveguide and an output waveguide comprising the steps of:
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selectively generating pump optical energy at a pumping wavelength; transmitting said pump optical energy toward said optical attenuator via a transmission path; selectively switching conditions along said transmission path between a first path condition for passing said pump optical energy to said optical attenuator and a second path condition for blocking said pump optical energy from said optical attenuator; passing an optical signal to said output waveguide of said optical system when said pump optical energy is passed to said optical attenuator via said transmission path; and attenuating said optical signal within said optical system when said pump optical energy is blocked from said optical attenuator. - View Dependent Claims (10, 11)
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12. An optical system for controlling optical signals comprising:
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a first input waveguide for guiding transmission of an optical signal; a first output waveguide, optically associated with said input waveguide, for guiding said transmission of said optical signal; an optical attenuator pump source, optically associated with said first output waveguide, having an output for continuously outputting optical energy; and a first individually controllable optical switch having; an optical attenuator optically connected to said optical attenuator pump source and located in a continuous optical path that includes said first input waveguide and said first output waveguide, said optical attenuator having a first condition in which said optical attenuator is in optical contact with optical energy at a pumping wavelength generated by said optical attenuator pump source such that said transmission of said optical signal is unattenuated by said optical attenuator, and having a second condition in which said optical attenuator is not in optical contact with optical energy at said pumping wavelength generated by said optical attenuator pump source such that said transmission of said optical energy is attenuated by said optical attenuator; and an optical attenuator pump source director, optically associated with said optical attenuator and said optical attenuator pump source, having a state in which optical energy output from said optical attenuator pump source is directed away from said optical attenuator. - View Dependent Claims (13, 14, 15, 16, 17, 18, 19, 20)
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Specification