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US 12,388,533 B2Granted
Linearized optical digital-to-analog modulator
AssigneeRamot at Tel-Aviv University Ltd.
InventorsYossef Ehrlichman, Ofer Amrani, Shlomo Ruschin
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Abstract
In a system for converting digital data into a modulated optical signal, an electrically controllable device, including a modulator having one or more actuating electrodes, provides an analog-modulated optical signal that is modulated in response to output data bits of a digital-to-digital mapping. A digital-to-digital conversion provides the mapping of input data words to the output data bits. The mapping enables adjustments to correct for non-linearities and other undesirable characteristics, thereby improving signal quality.
Claims19
An optical modulation system, the system comprising:
- an input for receiving digital input words, each digital input word comprising a plurality of input data bits;
- a laser for generating a continuous wave optical signal;
- a modulator receiving the continuous wave optical signal;
- and
- a mapper, wherein based on a mapping, the mapper maps a digital input word received at the input to a corresponding digital output word comprising a plurality of digital output data bits,
- wherein the mapping specifies, for each digital word included in a set of possible digital input words for the plurality of input data bits, a corresponding digital output word from a set of possible digital output words for the plurality of output data bits;
- wherein, for a first subset of increasing successive digital input word values specified in the mapping, values of digital output words in the set of possible digital output words, corresponding respectively to digital input words in the first subset, decrease;
- wherein, for a second subset of increasing successive digital input word values specified in the mapping, values of digital output words in the set of possible digital output words, corresponding respectively to digital input words in the second subset, increase;
- wherein the optical modulation system is enabled to generate one or more analog signals based on the mapped digital output word comprising the plurality of digital output data bits;
- and
- wherein the modulator modulates the continuous wave optical signal based on the one or more analog signals;
- thereby generating one or more analog modulated optical signal outputs for transmission over one or more optical fibers.
9 more elements
An optical modulation system, the system comprising:
- an input for receiving digital input words, each digital input word comprising a plurality of input data bits;
- a laser for generating a continuous wave optical signal;
- a modulator receiving the continuous wave optical signal;
- and
- a mapper, wherein based on a mapping, the mapper maps each digital input word included in a set of digital input words received at the input to a corresponding digital output word comprising a plurality of digital output data bits;
- wherein, for a first plurality of digital input words having increasing values and to which the mapping is applied, values of digital output words, corresponding respectively to the first plurality of digital input words, decrease;
- wherein, for a second plurality of digital input words having increasing values and to which the mapping is applied, values of digital output words, corresponding respectively to the second plurality of digital input words, increase;
- wherein the optical modulation system is enabled to generate one or more analog signals based on the mapped digital output words;
- and
- wherein the modulator modulates the continuous wave optical signal based on the one or more analog signals;
- thereby generating one or more analog modulated optical signal outputs for transmission over one or more optical fibers.
8 more elements
An optical modulation system, the system comprising:
- an input for receiving digital input words, each digital input word comprising a plurality of input data bits;
- a laser for generating a continuous wave optical signal;
- a modulator receiving the continuous wave optical signal, wherein the modulator comprises at least one electrode;
- and
- a mapper, and wherein based on a mapping, the mapper maps a digital input word received at the input to a corresponding digital output word comprising a plurality of digital output data bits;
- wherein the mapping specifies, for each digital word included in a set of possible digital input words for the plurality of input data bits, a corresponding digital output word from a set of possible digital output words for the plurality of output data bits;
- wherein for two successive input words received by the mapper, an analog voltage level based on the corresponding output words is either increased, decreased, or maintained the same to approximate to a desired modulation of an optical signal output as a function of the digital input words;
- and
- wherein the analog voltage level based on the corresponding output words is applied to at least one electrode of the modulator, thereby modulating the continuous wave optical signal and generating one or more analog modulated optical signal outputs for transmission over one or more optical fibers.
6 more elements
Dependencies are inferred from the claim text.