Modulation light signal generating device and FSK modulation signal generating device
AssigneeNational Institute of Information and Communications Technology, Incorporated Administrative Agency
InventorsTetsuya Kawanishi, Hiroshi Harada, Masayuki Izutsu
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Abstract
The object of the present invention is to provide a modulated optical signal generator utilizing the mechanism of a multiply optical modulator, and a modulated signal generator capable of outputting millimeter waves and the like utilizing the modulated optical signal generator. The above-mentioned object is solved by a modulated optical signal generator (1) provided with an optical modulator (2), a first optical filter (3), and a second optical filter (4), wherein a frequency of a multiplying optical modulation outputted from the second optical filter (4) is controlled by controlling the frequency of the modulating signal inputted to the optical modulator (2).
Claims6
An optical frequency shift keying modulator utilizing a reciprocating modulation, comprising:
- an optical modulator (2) modulating a light outputted by controlling a frequency of a modulating signal to generate a signal having side band frequencies of and f0−n1fm and f0+n2fm wherein f0 is frequency of input light, n1 and n2 are modulation order, and fm is frequency of modulation signal;
- a first optical filter (3) transmitting a light of a predetermined frequency domain among a light inputted to the optical modulator (2) and a light outputted from the optical modulator (2) while reflecting a light of other frequencies;
- a second optical filter (4) transmitting a light of a predetermined frequency domain among a light inputted to the optical modulator (2) and a light outputted from the optical modulator (2) while reflecting a light of other frequencies;
- and
- an RF signal source (5) generating the modulating signal inputted to the optical modulator (2);
- wherein said optical modulator (2) inputs said side band frequencies f0−n1fm and f0+n2fm to said second optical filter (4), and
- wherein said side band frequencies f0−n1fm and f0+n2fm are controlled by said optical frequency shift keying modulator by controlling the frequency of the modulating signal, fm, inputted to the optical modulator (2) in such a way that only one of the side band frequencies f0−n1fm and f0+n2fm falls within the predetermined frequency domain in which the second optical filter (4) transmits and said second optical filter of the optical frequency shift keying modulator outputs only one of the side band frequencies, and
- wherein the RF signal source controls the frequency of the modulating signal to be 1/T multiplied by an even number or an odd number, the T being a time for the light to be transmitted between the two optical filters.
Dependencies are inferred from the claim text.