Abstract: A frequency converter (1) for generating an output signal (5a) from an input signal (5), the output signal (5a) having different frequency than the input signal (5), the frequency converter (1) including: an input (7) for receiving an input signal (5); a transmission line (3) formed of a non-linear medium (3a), the medium (3a) arranged such that when the input signal (5) propagates along the line (3), one or more harmonics (5a,5b) of the input signal (5) are generated; a plurality of dispersion control elements (13), the dispersion control elements (13) arranged to control the dispersion relationship of the medium (3a), to phase match the input signal (5) and the one or more harmonics (5a,5b), such that energy is transferred from the input signal (5) to the one or more harmonics (5a,5b); and an output (9) for providing the one or more harmonics (5a, 5b) as an output signal.

Abstract: A four-wave mixing transmission line (3) including: an input (15, 17, 19) arranged to receive: a first pump signal (7a) having a first pump frequency; a second pump signal (7b), having a second pump frequency, different to the first pump frequency; and an input signal to be amplified (5); a non-linear medium (3a) having an intrinsic dispersion relationship, the medium (3a) arranged to allow interaction between the input signal (5), the first pump signal (7a) and the second pump signal (7b), such that the input signal (5) is amplified and an idler signal (9) is generated and amplified; and a plurality of dispersion control elements (31, 33, 49), the dispersion control elements (31, 33, 49) arranged to alter the dispersion relationship of the medium (3a) to diverge from the intrinsic dispersion relationship at one or more frequencies, such that the total phase difference between the input signal, (5) the first pump signal (7a), the second pump signal (7b) and the idler signal (9) is kept at zero or substantiall

Abstract: A frequency converter (1) for generating an output signal (5a) from an input signal (5), the output signal (5a) having different frequency than the input signal (5), the frequency converter (1) including: an input (7) for receiving an input signal (5); a transmission line (3) formed of a non-linear medium (3a), the medium (3a) arranged such that when the input signal (5) propagates along the line (3), one or more harmonics (5a,5b) of the input signal (5) are generated; a plurality of dispersion control elements (13), the dispersion control elements (13) arranged to control the dispersion relationship of the medium (3a), to phase match the input signal (5) and the one or more harmonics (5a,5b), such that energy is transferred from the input signal (5) to the one or more harmonics (5a,5b); and an output (9) for providing the one or more harmonics (5a, 5b) as an output signal.

Abstract: A four-wave mixing transmission line (3) including: an input (15, 17, 19) arranged to receive: a first pump signal (7a) having a first pump frequency; a second pump signal (7b), having a second pump frequency, different to the first pump frequency; and an input signal to be amplified (5); a non-linear medium (3a) having an intrinsic dispersion relationship, the medium (3a) arranged to allow interaction between the input signal (5), the first pump signal (7a) and the second pump signal (7b), such that the input signal (5) is amplified and an idler signal (9) is generated and amplified; and a plurality of dispersion control elements (31, 33, 49), the dispersion control elements (31, 33, 49) arranged to alter the dispersion relationship of the medium (3a) to diverge from the intrinsic dispersion relationship at one or more frequencies, such that the total phase difference between the input signal, (5) the first pump signal (7a), the second pump signal (7b) and the idler signal (9) is kept at zero or substantiall