Optical modulators as monolithically integrated optical isolators
First Claim
1. A monolithically integrated signal source and isolator apparatus for providing a stable, low frequency chirp source device for high-speed fiber-optic data transmission, comprising:
- a laser light source utilized as the signal source;
a first modulator driven to be synchronous with a transmitted data stream from the signal source;
a second modulator driven to be synchronous with the transmitted data stream, wherein the second modulator is sequentially arranged and spaced a distance apart from the first modulator to provide a phase delay between them, and wherein the modulators generate a timed sequence of open gates which permit transmission of a data signal in a forward direction and attenuate a reverse direction signal; and
a semiconductor substrate, with the laser light source and the first and second modulators monolithically integrated on the semiconductor substrate.
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Accused Products
Abstract
An apparatus and technique for providing isolation for a signal source utilizing two or more modulators is described. In particular, the apparatus generates a timed sequence of "open gates" that are synchronized to the data signal which permit transmission in a forward direction, and which attenuate a reverse direction signal. Another embodiment attenuates primarily reflected light signals by utilizing a passive waveguide and a modulator. The passive waveguide provides a propagation delay such that signals reflected from its end facet are attenuated by the modulator. The apparatus is suitable for use as an isolator for a light source in a high-speed optical fiber data transmission system.
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Citations
33 Claims
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1. A monolithically integrated signal source and isolator apparatus for providing a stable, low frequency chirp source device for high-speed fiber-optic data transmission, comprising:
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a laser light source utilized as the signal source; a first modulator driven to be synchronous with a transmitted data stream from the signal source; a second modulator driven to be synchronous with the transmitted data stream, wherein the second modulator is sequentially arranged and spaced a distance apart from the first modulator to provide a phase delay between them, and wherein the modulators generate a timed sequence of open gates which permit transmission of a data signal in a forward direction and attenuate a reverse direction signal; and a semiconductor substrate, with the laser light source and the first and second modulators monolithically integrated on the semiconductor substrate. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8)
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9. A monolithically integrated signal source and isolator apparatus for the high speed fiber-optic transmission of data, comprising:
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an unmodulated signal source; a first modulator connected to the source for encoding the source signal to generate an RZ modulated data signal; a second modulator sequentially connected to, and spaced apart from, the first modulator to provide a phase delay between them, wherein the modulators generate a timed sequence of open gates which permit a data stream to be transmitted in a forward direction, and attenuate a reverse direction signal; and a semiconductor substrate, with the unmodulated laser signal source and the first and second modulators monolithically integrated on the semiconductor substrate. - View Dependent Claims (10, 11)
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12. A monolithically integrated apparatus for the high-speed fiber-optic transmission of data comprising:
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a source means for transmitting an RZ modulated signal; a first modulator means connected to the source means, driven to be synchronous with the RZ signal; a second modulator means sequentially connected to the first modulator means, driven to be synchronous with the RZ signal, wherein the second modulator means is spaced apart from the first modulator means to provide a phase delay between them such that the first and second modulator means generate a timed sequence of open gates which permit data transmission in a forward direction, and attenuate a reverse direction signal; and a semiconductor substrate, with the source means and the first and second modulator means monolithically integrated on the semiconductor substrate. - View Dependent Claims (13, 14, 15, 16, 17)
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18. A monolithically integrated apparatus for the high speed fiber-optic transmission of data, comprising:
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an unmodulated source means for providing a light signal; a first modulator means connected to the source means driven to encode the light signal to generate an RZ modulated data signal; a second modulator means sequentially connected to the first modulator means, driven to be synchronous with the RZ data signal, wherein the second modulator means is spaced apart from the first modulator means to provide a phase delay between them such that the first and second modulator means generate a timed sequence of open gates that permit data transmission in a forward direction and attenuate a reverse direction signal; and a semiconductor substrate, with the unmodulated source means and the first and second modulator means monolithically integrated on the semiconductor substrate. - View Dependent Claims (19, 20, 21, 22, 23)
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24. A method for providing isolation for a stable, low frequency chirp signal source for high speed fiber-optic data transmission, comprising:
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connecting a first and a second modulator to said signal source while monolithically integrating the first and second modulators and said signal source on a semiconductor substrate; sequentially spacing the second modulator at a distance from the first modulator to provide a predetermined time delay; driving the first modulator to be synchronous with a transmitted data signal from the signal source to produce a first sequence of open gates; driving the second modulator to be synchronous with the transmitted data signal to produce a second sequence of open gates, wherein the second sequence of open gates is delayed in time from the first sequence of open gates; transmitting data signals in a forward direction through the open gates of the first and second modulators; and attenuating a reverse direction signal. - View Dependent Claims (25, 26, 27)
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28. A method for providing isolation for a device containing a signal source and a plurality of sequentially arranged modulators, comprising:
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monolithically integrating the signal source and the plurality of sequentially arranged modulators on a semiconductor substrate; generating a signal with the signal source; driving a first modulator of the plurality of modulators to encode the signal to produce an encoded data signal; driving each of the other modulators to generate a timed sequence of open gates that are synchronous with the encoded data signal; and arranging the modulators to have a spatial separation to realize a sequence of timed open gates having a phase delay between them, wherein transmission of the encoded data signal is permitted in a forward direction and a reverse direction signal is attenuated. - View Dependent Claims (29)
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30. A method for providing isolation for an apparatus containing a laser source and a plurality of sequentially arranged modulators, comprising:
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monolithically integrating the laser source and the plurality of sequentially arranged modulators on a semiconductor substrate; transmitting an RZ modulated data signal; driving each modulator to generate a timed sequence of open gates that are synchronous with the RZ signal; and arranging at least two of the modulators to have a spatial separation which provides a time delay between them that is greater or equal to one-half the duration of the open gate and less than or equal to one-half of the time period consisting of the RZ duration signal minus the duration of an open gate, wherein transmission in a forward direction is permitted and a reverse direction signal is attenuated. - View Dependent Claims (31)
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32. A method for providing isolation for an apparatus containing a light source and a plurality of sequentially arranged modulators, comprising:
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monolithically integrating the light source and the plurality of sequentially arranged modulators on a semiconductor substrate; generating a light signal with the light source; driving a first modulator of the plurality of modulators to encode the light signal to produce an RZ modulated data signal; driving each of the other modulators to generate a timed sequence of open gates that are synchronous with the RZ data signal; and arranging the modulators to have a spatial separation to realize a sequence of timed open gates having a phase delay between them, wherein transmission of the RZ data stream is permitted in a forward direction and a reverse direction signal is attenuated. - View Dependent Claims (33)
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Specification