Coherent THz emitter with DC power reducing resistor
AssigneeTeraView Limited
InventorsBryan E. Cole, Michael J. Evans, Julian A. Cluff
Life of this patent
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Abstract
An emitter for emitting radiation in a first range of frequencies comprising: a photoconductive material (11); and first and second contact elements (12, 13, 14) separated by a photoconducting gap provided by said photoconducting material (11), for applying a bias across said photoconducting gap, wherein at least one of said first and second contact elements (12, 13, 14) comprises a resistive element (14) for restricting current flow between said first and second contact elements in a second range of frequencies lower than the first range of frequencies.
Claims26
An emitter for emitting radiation in a first range of frequencies comprising:
- a photoconductive material;
- and
- first and second contact elements separated by a photoconducting gap provided by said photoconducting material, for applying a bias across said photoconducting gap,
- wherein at least one of said first and second contact elements comprises a resistive element for restricting current flow between said first and second contact elements in a second range of frequencies lower than the first range of frequencies.
A method of determining a resistive value for use as a biasing resistance in a terahertz emitter, comprising:
- determining a value indicative of a repetition frequency of an excitation laser;
- determining a value indicative of a capacitance of the emitter;
- and
- calculating the resistive value by equating the value indicative of the repetition frequency with an RC-time constant of the terahertz emitter.
A method for determining a resistive value, R, for use as a series biasing resistance in a terahertz emitter comprising a photoconductive substrate and an antenna electrode on the substrate surface, the method comprising:
- determining the resistive value using the formula:
- A=1/(RC)
- where A is a repetition frequency of an excitation laser and C is the capacitance of the antenna electrode.
A system for generating THz radiation, comprising:
- an emitter comprising a photoconductive material and first and second contact elements separated by a photoconducting gap provided by said photoconducting material for applying a bias across said photoconducting gap,
- a bias signal source for said emitter configured to output and AC signal;
- and
- a step-up transformer located between said bias signal source and said emitter.
Dependencies are inferred from the claim text.