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US 6,400,871 B1Granted
Phase control mechanism for coherent fiber amplifier arrays
AssigneeHRL Laboratories, LLC
InventorMonica Minden
Life of this patent
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Abstract
A phase control system configured for application with coherent fiber amplifier arrays. The invention advantageously utilizes existing fiber amplifiers to modulate array elements material properties of the fiber amplifier arrays; specifically, the arrays may be phased up or steered via modulation of their pump lasers. There are both thermal and index of refraction changes in the fiber when the pump light is absorbed. This invention specifically addresses using the pump light already present in fiber amplifiers to effect desired phase control, and to enable arrays of fibers to be coherently phased and steered via amplifier pumps additionally the degree of phasing may be adjusted using adaptive optic feedback techniques.
Claims38
A phase control apparatus for a coherent fiber amplifier array comprising:
- i. a coherent source of electromagnetic radiation;
- ii. a first length of electromagnetic radiation conducting fiber having a first and a second end;
- iii. at least one fiber coupler configured to accept a single fiber input and provide a plurality of fiber outputs;
- iv. a plurality of secondary lengths of electromagnetic radiation-conducting fiber wherein each length has a first and a second end;
- v. a plurality of electromagnetic radiation-amplifying pumps configured to have modulated pump input;
- vi. a means for binding a plurality of fibers in an array without substantially encumbering electromagnetic radiation from the fiber outputs from said second ends of said plurality of secondary lengths of electromagnetic radiation-conducting fibers;
- vii. a plurality of micro lenses configured to condition an output from said second ends of said plurality secondary lengths of electromagnetic radiation conducting fibers;
- and a means for independently controlling the amplitude modulation of the pump radiation to control the phase of each amplifier fiber;
- wherein,
- a. said coherent source of electromagnetic radiation provides an electromagnetic radiation input to said first end of said first length of electromagnetic radiation-conducting fiber;
- and
- b. said second end of said first length of electromagnetic radiation conducting fiber provides an input to said at least one fiber coupler configured to accept a single fiber input and provide a plurality of fiber outputs;
- wherein
- c. said fiber outputs are bound in an array, wherein said array is configured such that said plurality of fibers are in a substantially planar array and that the output from the fibers is substantially unencumbered;
- and wherein,
- d. before said plurality of second lengths of electromagnetic radiation-conduction fibers reach said array, said fibers are coupled to a plurality of electromagnetic radiation-amplifying pumps;
- and wherein,
- e. said output of said substantially unencumbered planar array of fibers is conditioned by a plurality of micro lenses;
- and a means is provided for controlling the modulated output of said electromagnetic radiation amplifying pumps.
16 more elements
A method for controlling the phase of a coherent fiber amplifier array comprising the following steps:
- i. providing a coherent source of electromagnetic radiation;
- ii. providing a first length of electromagnetic radiation-conducting fiber having a first and a second end;
- iii. providing at least one fiber coupler configured to accept a single fiber input and provide a plurality of fiber outputs;
- iv. providing a plurality of secondary lengths of electromagnetic radiation-conducting fiber wherein each length has a first and a second end;
- v. providing a plurality of electromagnetic radiation-amplifying pumps configured to provide modulated output;
- vi. providing a means for binding a plurality of second lengths of fiber in an array without substantially encumbering the electromagnetic radiation output from said second ends of said plurality of secondary providing lengths of electromagnetic radiation-conducting fibers;
- vii. providing a plurality of micro lenses configured to condition an output from said second ends of said plurality secondary lengths of electromagnetic radiation-conducting fibers;
- and
- viii. providing a means for independently controlling the amplitude modulation of the pump radiation to control the phase of each amplifier fiber;
- wherein
- a. said coherent source of electromagnetic radiation provides an electromagnetic radiation input to said first end of said first length of electromagnetic radiation-conducting fiber;
- and
- b. said second end of said first length of electromagnetic radiation conducting fiber provides an input to said at least one fiber coupler configured to accept a single fiber input and provide a plurality of fiber outputs;
- wherein
- c. said fiber outputs are bound in an array, wherein said array is configured such that said plurality of second lengths of fiber are in a substantially planar array and that the output from the fibers is substantially unencumbered;
- and wherein,
- d. before said plurality of electromagnetic radiation-conduction fibers reach said array, said fibers arc coupled to a plurality of electromagnetic radiation-amplifying pumps;
- and wherein,
- e. said output of said substantially unencumbered planar array of fibers is conditioned by a plurality of micro lenses;
- and a means is provided for controlling the modulated output of said electromagnetic radiation amplifying pumps.
17 more elements
Dependencies are inferred from the claim text.