Optical frequency conversion device

Claim 2

An optical apparatus for generating an optical frequency comb having a plurality of optical carrier frequencies, each spaced apart from another by an offset frequency, said optical apparatus comprising: means for frequency translating an input optical signal having a first optical carrier frequency to an output optical signal having a second optical carrier frequency; means for optically amplifying said output optical signal into an amplified output optical signal; and means for optically recirculating a portion of said amplified output optical signal to said means for frequency translating as a recirculated input optical signal, thereby forming a recirculating loop so that with repeated transits within said loop said recirculated input optical signal is both frequency translated and optically amplified such that said optical frequency comb is generated.

Claim 3

The optical apparatus as defined in claim 1 wherein said means for optically amplifying has an optical gain substantially sufficient to compensate for optical loss in said recirculating loop.

Claim 4

The optical apparatus as defined in claim 2 further comprising means for coupling optically said input optical signal to said means for frequency translating.

Claim 5

The optical apparatus as defined in claim 3 further comprising output means for coupling optically said optical frequency comb said recirculating loop.

Claim 6

The optical apparatus as defined in claim 4 wherein said means for frequency translating includes a Bragg cell operating at an acoustic wave frequency f a .

Claim 7

The optical apparatus as defined in claim 5 wherein said Bragg cell includes TeO 2 .

Claim 8

The optical apparatus as defined in claim 5 wherein said Bragg cell includes LiNbO 3 .

Claim 9

The optical apparatus as defined in claim 5 wherein said Bragg cell includes InP.

Claim 10

The optical apparatus as defined in claim 5 wherein said means for optically recirculating includes a linear optical cavity.

Claim 11

The optical apparatus as defined in claim 9 wherein said offset frequency is twice said acoustic wave frequency.

Claim 12

The optical apparatus as defined in claim 5 wherein said means for optically recirculating includes a loop optical cavity.

Claim 13

The optical apparatus as defined in claim 11 wherein said offset frequency is said acoustic wave frequency.

Claim 14

The optical apparatus as defined in claim 5 wherein said means for optically amplifying includes a semiconductor optical amplifier.

Claim 15

The optical apparatus as defined in claim 5 wherein said means for optically amplifying includes an Erbium-doped fiber optical amplifier.

Claim 16

The optical apparatus as defined in claim 13 further comprising means coupled optically to the input optical signal coupling means for optically modulating said input optical signal.

Claim 17

The optical apparatus as defined in claim 15 wherein said means for optically modulating includes an electro-optic modulator.

Claim 18

The optical apparatus as defined in claim 16 further comprising means for filtering a predetermined spectral region of said input optical signal for limiting the gain-bandwidth of said recirculating loop.

Claim 19

The optical apparatus as defined in claim 17 wherein said means for filtering includes a Fabry-Perot etalon.

Claim 20

A photonic switch for converting the optical carrier frequency of an input optical signal to a different predetermined optical carrier frequency, said photonic switch comprising: first means for selecting said input optical signal from among wavelength division multiplexed optical signals; means for frequency translating said input optical signal having a first optical carrier frequency to an output optical signal having a second optical carrier frequency; means for optically amplifying said output optical signal into an amplified output optical signal; means for optically recirculating a portion of said amplified output optical signal to said means for frequency translating as a recirculated input optical signal, thereby forming a recirculating loop so that with repeated transits within said loop said recirculated input optical signal is both frequency translated and optically amplified such that an optical frequency comb is generated, said optical frequency comb having a plurality of optical carrier frequencies, each spaced by an offset frequency; and second means for selecting one of said plurality of optical carrier frequencies corresponding to said different predetermined optical carrier frequency.

Claim 21

A photonic switch for converting the optical carrier frequency of an input optical signal to a different predetermined optical carrier frequency, said photonic switch comprising: first means for selecting said input optical signal from among wavelength division multiplexed optical signals; means for frequency translating said input optical signal having a first optical carrier frequency to an output optical signal having a second optical carrier frequency; means for optically amplifying said output optical signal into an amplified output optical signal; means for optically recirculating a portion of said amplified output optical signal to said means for frequency translating as a recirculated input optical signal, thereby forming a recirculating loop so that with repeated transits within said loop said recirculated input optical signal is both frequency translated and optically amplified such that an optical frequency comb is generated, said optical frequency comb having a plurality of optical carrier frequencies, each spaced by an offset frequency; and second means for selecting one of said plurality of optical carrier frequencies corresponding to said different predetermined optical carrier frequency.

Claim 22

The photonic switch as defined in claim 19 wherein said first means for selecting said input optical signal includes a Fabry-Perot etalon.

Claim 23

The photonic switch as defined in claim 20 wherein said second means for selecting one of said plurality of optical carrier frequencies includes a Fabry-Perot etalon.

Claim 24

An optical apparatus for locking the carrier frequency of an input optical signal generated by an optical signal source to a predetermined optical carrier frequency, said predetermined carrier frequency offset from an reference optical frequency by an integer multiple, said optical apparatus comprising; means for frequency translating said input optical signal having a first optical carrier frequency to an output optical signal having a second optical carrier frequency; means for optically amplifying said output optical signal into an amplified output optical signal; means for optically recirculating a portion of said amplified output optical signal to said means for frequency translating as a recirculated input optical signal, thereby forming a recirculating loop so that with repeated transits within said loop said recirculated input optical signal is both frequency translated and optically amplified such that an optical frequency comb is generated, said optical frequency comb having a plurality of optical carrier frequencies, each spaced from each other by an offset frequency. means coupled to said optical signal source for varying the optical carrier frequency of said optical signal in response to a control signal; and means responsive to the presence of said reference optical frequency for generating said control signal for said means for varying the optical carrier frequency to lock said optical signal source to an integer multiple of said reference optical frequency.

Claim 25

An optical apparatus for locking the carrier frequency of an input optical signal generated by an optical signal source to a predetermined optical carrier frequency, said predetermined carrier frequency offset from an reference optical frequency by an integer multiple, said optical apparatus comprising; means for frequency translating said input optical signal having a first optical carrier frequency to an output optical signal having a second optical carrier frequency; means for optically amplifying said output optical signal into an amplified output optical signal; means for optically recirculating a portion of said amplified output optical signal to said means for frequency translating as a recirculated input optical signal, thereby forming a recirculating loop so that with repeated transits within said loop said recirculated input optical signal is both frequency translated and optically amplified such that an optical frequency comb is generated, said optical frequency comb having a plurality of optical carrier frequencies, each spaced from each other by an offset frequency. means coupled to said optical signal source for varying the optical carrier frequency of said optical signal in response to a control signal; and means responsive to the presence of said reference optical frequency for generating said control signal for said means for varying the optical carrier frequency to lock said optical signal source to an integer multiple of said reference optical frequency.

Claim 26

The optical apparatus as defined in claim 22 wherein said means responsive to the presence of said reference optical frequency includes an optogalvanic cell.

Claim 27

An optical apparatus for measuring the offset frequency from a reference optical frequency V ref of an input optical signal having a first optical carrier frequency υ o , said optical apparatus comprising; means for frequency translating said input optical signal having said first optical carrier frequency to an output optical signal having a second optical carrier frequency; means for optically amplifying said output optical signal into an amplified output optical signal; means for optically recirculating a portion of said amplified output optical signal to said means for frequency translating as a recirculated input optical signal, thereby forming a recirculating loop so that with repeated transits within said loop said recirculated input optical signal is both frequency translated and optically amplified such that an optical frequency comb is generated, said optical frequency comb having a plurality of optical carrier frequencies, each spaced from another by a tunable offset frequency; means, coupled to said means for frequency translating, for varying said tunable offset frequency to f 1 and f 2 in response to first and second control signals, respectively; and means, responsive to the presence of said reference optical frequency, V ref for generating said first and second control signals, said first control signal corresponding to the optical carrier frequency of said input optical signal being offset by an amount mf 1 from said reference optical frequency, where m is an integer, and said second control signal corresponding to the optical carrier frequency of said input optical signal being offset by an amount (m+1)f 2 from said reference optical frequency, wherein by solving for m said offset frequency can be determined.

Claim 28

An optical apparatus for measuring the offset frequency from a reference optical frequency V ref of an input optical signal having a first optical carrier frequency υ o , said optical apparatus comprising; means for frequency translating said input optical signal having said first optical carrier frequency to an output optical signal having a second optical carrier frequency; means for optically amplifying said output optical signal into an amplified output optical signal; means for optically recirculating a portion of said amplified output optical signal to said means for frequency translating as a recirculated input optical signal, thereby forming a recirculating loop so that with repeated transits within said loop said recirculated input optical signal is both frequency translated and optically amplified such that an optical frequency comb is generated, said optical frequency comb having a plurality of optical carrier frequencies, each spaced from another by a tunable offset frequency; means, coupled to said means for frequency translating, for varying said tunable offset frequency to f 1 and f 2 in response to first and second control signals, respectively; and means, responsive to the presence of said reference optical frequency, V ref for generating said first and second control signals, said first control signal corresponding to the optical carrier frequency of said input optical signal being offset by an amount mf 1 from said reference optical frequency, where m is an integer, and said second control signal corresponding to the optical carrier frequency of said input optical signal being offset by an amount (m+1)f 2 from said reference optical frequency, wherein by solving for m said offset frequency can be determined.

Claim 29

The optical apparatus as defined in claim 24 wherein said means responsive to the presence of said reference optical frequency includes an optogalvanic cell.