Optical modulating device with frequency multiplying technique for electrical signals

• US 20100008680A1
• Filed: 04/02/2009
• Published: 01/14/2010
• Est. Priority Date: 11/07/2008
• Status: Active Grant

• Current Assignee: National Chiao Tung University (Government of The Republic of China)
• Original Assignee: National Chiao Tung University (Government of The Republic of China)
• Inventors: Chen, Jyehong, Shih, Po-Tsung, Dai, Sheng-Peng, Chi, Sien, Peng, Peng-Chun, Lin, Chun-Ting
• Granted Patent: US 8,184,988 B2
• Time in Patent Office: Days
• US Class Current: 398/198
• CPC Class Codes: H04B 10/505 using external modulation
• CPC Class Codes: H04B 10/548 Phase or frequency modulation

Abstract

The present invention relates to an optical modulating device with frequency multiplying technique for electrical signals, which primary comprises a mixer, which generates a mixed data signal from a first electrical signal and a second electrical signal. The mixed data signal is then received by a first phase shift device to have its phase shifted and becomes a first shifted signal. The first electrical signal is further received by a second phase shift device to have its phase shifted and becomes a second shifted signal. The present invention further comprises an integrated electro-optic modulator (Mach-Zehnder modulator), which is used to receive an input optical signal, the mixed data signal, the first shifted signal, the second shifted signal and the first electrical signal mentioned above, the integrated electro-optic modulator will then modulates the input optical signal into a frequency multiplying output optical signal that carries the first electrical signal and the second electrical signal. The present invention can carry and transmit amplitude shift keying signals and vector modulation signals, thereby provides a more advanced optical communication transmission service.

Claims

1. An optical modulating device with frequency multiplying technique for electrical signals comprising:

an electrical signal generator, which generates a first electrical signal;

a mixer, which receives said first electrical signal and a second electrical signal, then generates and sends out a mixed data signal;

a first phase shift device, which receives and shifts phase of said mixed data signal, then sends out a first shifted signal;

a second phase shift device, which receives and shifts phase of said first electrical signal, then sends out a second shifted signal;

an optical signal generator, which generates a input optical signal; and

an integrated electro-optic modulator (Mach-Zehnder modulator), which receives said input optical signal, said mixed data signal, said first shifted signal, said second shifted signal and said first electrical signal, then modulates said input optical signal into a frequency multiplying output optical signal that carries said first electrical signal and said second electrical signal.

2. The optical modulating device with frequency multiplying technique for electrical signals according to claim 1, wherein said integrated electro-optic modulator further comprises:

a first electro-optic modulating unit, which receives said input optical signal, said mixed data signal and said second shifted signal, when said first electro-optic modulating unit is being biased, it affects transmission characteristic of said input optical signal, allowing said input optical signal to be modulated by said mixed data signal and said second shifted signal to generate a first optical signal;

a second electro-optic modulating unit, which receives said input optical signal, said first electrical signal and said first shifted signal, when said second electro-optic modulating unit is being biased, it affects transmission characteristic of said input optical signal, allowing said input optical signal to be modulated by said first electrical signal and said first shifted signal to generate a second optical signal; and

a third electro-optic modulating unit, which receives said first optical signal and said second optical signal, when said third electro-optic modulating unit is being biased, it affects transmission characteristic of said first optical signal and said second optical signal and generates said frequency multiplying output optical signal.

3. The optical modulating device with frequency multiplying technique for electrical signals according to claim 2, wherein phase of said first shifted signal and said mixed data signal is different by 90 degrees.

4. The optical modulating device with frequency multiplying technique for electrical signals according to claim 2, wherein phase of said second shifted signal and said first electrical signal is different by 90 degrees.

5. The optical modulating device with frequency multiplying technique for electrical signals according to claim 1, wherein said first electrical signal is a sine signal.

6. The optical modulating device with frequency multiplying technique for electrical signals according to claim 1, wherein said second electrical signal is an amplitude shift modulation signal, a vector modulation signal, a phase shift modulation signal, a quadrature amplitude modulation signal or an orthogonal frequency division multiplexing signal.

7. The optical modulating device with frequency multiplying technique for electrical signals according to claim 1 further comprises a signal splitter, which receives said first electrical signal from said electrical signal generator, then sends said first electrical signal to said mixer and said second phase shift device separately.

8. The optical modulating device with frequency multiplying technique for electrical signals according to claim 1, wherein said optical signal generator is a laser diode.

9. The optical modulating device with frequency multiplying technique for electrical signals according to claim 1, wherein said frequency multiplying output optical signal is a frequency doubling output optical signal.

10. The optical modulating device with frequency multiplying technique for electrical signals according to claim 2 further comprises an adder, which receives and adds said mixed data signal and said second shifted signal, then sends resulting signal to said first electro-optic modulating unit.

11. The optical modulating device with frequency multiplying technique for electrical signals according to claim 2, further comprises an adder, which receives and adds said first electrical signal and said first shifted signal, then sends resulting signal to said second electro-optic modulating unit.

12. The optical modulating device with frequency multiplying technique for electrical signals according to claim 1, wherein after said first phase shift device shifted phase of said mixed data signal, said first phase shift device can further send said mixed data signal and said first shifted signal to said integrated electro-optic modulator.

13. The optical modulating device with frequency multiplying technique for electrical signals according to claim 1, wherein said first shifted signal from said first phase shift device can go through a micro phase shifter to have its phase more precisely adjusted before sending to said integrated electro-optic modulator, allowing said first shifted signal and said mixed data signal have phase different by exactly 90 degrees.

14. The optical modulating device with frequency multiplying technique for electrical signals according to claim 1, wherein after said second phase shift device shifted phase of said first electrical signal, said first phase shift device can further send said first electrical signal and said second shifted signal to said integrated electro-optic modulator.

15. The optical modulating device with frequency multiplying technique for electrical signals according to claim 1, wherein said second shifted signal from said second phase shift device can go through a micro phase shifter to have its phase more precisely adjusted before sending to said integrated electro-optic modulator, allowing said second shifted signal and said first electrical signal have phase different by exactly 90 degrees.

16. The optical modulating device with frequency multiplying technique for electrical signals according to claim 2, wherein bias value for said first electro-optic modulating unit and said second electro-optic modulating unit is V_π

and bias value for said third electro-optic modulating unit has bias value is V_π

/2.