High power pulse shaping fiber laser for high data rate free space telecommunication systems

• US 20050036525A1
• Filed: 04/15/2004
• Published: 02/17/2005
• Est. Priority Date: 04/15/2003
• Status: Active Grant

• Current Assignee: Liu Jian
• Original Assignee: Liu Jian
• Inventors: Liu, Jian
• Granted Patent: US 7,256,930 B2
• Time in Patent Office: Days
• US Class Current: 372/6
• CPC Class Codes: H01S 3/005 Optical devices external to the laser cavity, specially adapted for lasers, e.g. for homogenisation of the beam or for manipulating laser pulses, e.g. pulse shaping shaping laser beam for working metal or other materials B23K26/06; optical elements, systems or apparatus in general G02B
• CPC Class Codes: H01S 3/0078 Frequency filtering
• CPC Class Codes: H01S 3/0085 Modulating the output, i.e. the laser beam is modulated outside the laser cavity
• CPC Class Codes: H01S 3/06708 Constructional details of the fibre, e.g. compositions, cross-section, shape or tapering optical fibres as passive waveguides G02B6/02
• CPC Class Codes: H01S 3/0675 Resonators including a grating structure, e.g. distributed Bragg reflectors [DBR] or distributed feedback [DFB] fibre lasers
• CPC Class Codes: H01S 3/06758 Tandem amplifiers
• CPC Class Codes: H01S 3/0941 of a laser diode
• CPC Class Codes: H01S 3/1608 erbium

Abstract

An amplified laser source for amplifying a laser projection that includes a diode laser source modulated by a pulse generator applying an alternate high and low voltages higher and lower than a threshold voltage for projecting a modulated optical signal. The laser source further includes a first erbium-doped fiber (EDF) for amplifying the modulated optical signal. The laser source further includes a set of Bragg gratings for receiving the modulated optical signal from the first EDF for reflecting a grating-specific pulse-distortion-reduced optical signal. The laser source further includes an electro-absorption (EA) modulator synchronized with the pulse generator for increasing an extinction ratio of the optical signals. The laser source further includes a second erbium doped fiber (EDF) for receiving and amplifying the optical signal from the EA modulator wherein the second erbium doped fiber (EDF) having a length of several meters and a diameter greater than or equal to thirty-five micrometers.

Claims

1. An amplified laser source for amplifying a laser projection comprising:

a diode laser source modulated by a pulse generator applying an alternate high and low voltages higher and lower than a threshold voltages projecting a modulated optical signal;

a first erbium doped fiber (EDF) for amplifying said modulated optical signal; and

a set of Bragg gratings for receiving said modulated optical signal from said first EDF for reflecting a grating-specific pulse-distortion-reduced optical signal.

2. The amplified laser source of claim 1 further comprising:

an EA modulator synchronized with said pulse generator for increasing an extinction ratio of said optical signals.

3. The amplified laser source of claim 2 further comprising:

a second erbium doped fiber (EDF) for receiving and amplifying said optical signal from said Electro-Absorption (EA) modulator.

4. The amplified laser source of claim 3 wherein:

said second erbium doped fiber (EDF) having a large mode area.

5. The amplified laser source of claim 3 wherein:

said second erbium doped fiber (EDF) having a length of several meters and a diameter greater than or equal to thirty-five micrometers.

6. The amplified laser source of claim 2 wherein:

said EA modulator is a semiconductor Electro-Absorption (EA) modulator.

7. An amplified laser source for amplifying a laser projection comprising:

a diode laser source modulated by a pulse generator applying an alternate high and low voltages higher and lower than a threshold voltages projecting a modulated optical signal;

a first erbium doped fiber (EDF) for amplifying said modulated optical signal;

a set of Bragg gratings for receiving said modulated optical signal from said first EDF for reflecting a grating-specific pulse-distortion-reduced optical signal;

an EA modulator synchronized with said pulse generator for increasing an extinction ratio of said optical signals; and

a second erbium doped fiber (EDF) for receiving and amplifying said optical signal from said EA modulator wherein said second erbium doped fiber (EDF) having a length of several meters and a diameter greater than or equal to thirty-five micrometers.

8. An amplified laser source for amplifying a laser projection comprising:

a set of Bragg gratings for reflecting a grating-specific pulse-distortion-reduced optical signal.

9. The amplified laser source of claim 8 further comprising:

a diode laser source modulated by a pulse generator applying an alternate high and low voltages higher and lower than a threshold voltages projecting a modulated optical signal to said Bragg gratings.

10. The amplified laser source of claim 9 further comprising:

a first erbium doped fiber (EDF) for amplifying said modulated optical signal.

11. The amplified laser source of claim 8 further comprising:

an EA modulator synchronized with said pulse generator for increasing an extinction ratio of said optical signals.

12. The amplified laser source of claim 11 further comprising:

a second erbium doped fiber (EDF) for receiving and amplifying said optical signal from said EA modulator.

13. The amplified laser source of claim 12 wherein:

said second erbium doped fiber (EDF) having a large mode area.

14. The amplified laser source of claim 12 wherein:

said second erbium doped fiber (EDF) having a length of several meters and a diameter greater than or equal to thirty-five micrometers.

15. The amplified laser source of claim 11 wherein:

said EA modulator is a semiconductor EA modulator.

16. A method for configuring an amplified laser source for amplifying a laser projection comprising:

employing a set of Bragg gratings for reflecting a grating-specific pulse-distortion-reduced optical signal.

17. The method of claim 16 further comprising:

modulating a diode laser source by a pulse generator applying an alternate high and low voltages higher and lower than a threshold voltages for projecting a modulated optical signal to said Bragg gratings.

18. The method of claim 17 further comprising:

amplifying an optical signal from said diode laser by a first erbium doped fiber (EDF).

19. The method of claim 17 further comprising:

transmitting said optical signals via an EA modulator synchronized with said pulse generator.

20. The method of claim 18 further comprising:

implementing a second erbium doped fiber (EDF) for receiving and amplifying said optical signal from said EA modulator.

21. The method of claim 20 wherein:

said step implementing a second EDF is a step of implementing said second erbium doped fiber (EDF) having a large mode area.

22. The method of claim 20 wherein:

said step implementing a second EDF is a step of implementing said second erbium doped fiber (EDF) having a length of several meters and a diameter greater than or equal to thirty-five micrometers.

23. The method of claim 19 wherein:

transmitting said optical signals via an EA modulator is a step of transmitting said optical signals via a semiconductor EA modulator.