Optical transmitter receiver for free space optical communication and network system and application apparatus thereof

• US 20040091270A1
• Filed: 07/31/2003
• Published: 05/13/2004
• Est. Priority Date: 08/01/2001
• Status: Abandoned Application

• Current Assignee: Institute of Information Technology Assessment, Lumenlink Company Limited
• Original Assignee: Institute of Information Technology Assessment, Lumenlink Company Limited
• Inventors: Cho, Kyuman, Choi, Youngwan
• Application Number:
  US10/381,817
• Publication Number:
  US 20040091270A1
• Time in Patent Office: Days
• US Class Current: 398/130
• CPC Class Codes: H04B 10/1149 Arrangements for indoor wireless networking of information
• CPC Class Codes: H04B 10/40 Transceivers

Abstract

The present invention relates to the optical transmitter, receiver and application apparatus thereof for OWLL (Optical WireLess Link) which transmits and receives the optical signals through the free space and FSON (Free Space Optical Network) system using OWLL. Photonic devices such as laser diode and photo detector and electronics for driving the photonic devices are formed directly on a single printed circuit board as a standardized module and the PCB is assembled with optical instrument which is also manufactured as a standardized optical module. Then, the optical transmitter, receiver and application apparatus thereof becomes small, light, cost-effective, multi-functional and reliable.

Claims

1. A transmitter for Free Space Optical Communication comprising:

a light source formed on a printed circuit board;

a photo detector formed on said printed circuit board for detecting the light from said light source;

a current driver and controller circuit integrally formed on said printed circuit board having a first terminal for receiving input signals, a second terminal for bias-in, a third terminal connected to said light source for outputting output signals to said light source and a fourth terminal connected to said photo detector for receiving output control signals for controlling the output of said light source from said photo detector;

an optics module formed to be assembled with said printed circuit board for receiving the light from said light source and transmitting the received light to the external free space.

2. The transmitter of claim 1, wherein

said light source is a laser diode or a light emitting diode.

3. The transmitter of claim 1, wherein

said light source and said photo detector are bonded to said printed circuit board using flip-chip bonding method.

4. The transmitter of claim 1, wherein said current driver and controller circuit comprises:

a light source driver circuit for driving said light source by outputting pulse via said first terminal; and

an automatic output control circuit for controlling the output of said light source driver circuit according to the output control signal inputted via said fourth terminal.

5. The transmitter of claim 1, wherein said optics module comprises:

a lens; and

a lens holder being able to adjust the focal length of said lens.

6. The transmitter of claim 1, wherein

said lens is an aspheric lens or a Fresnel lens.

7. The transmitter of claim 1, wherein

the output power of said light source and the magnitude of driving current of said current driver and controller circuit are adjusted to have appropriate values according to the transmission distance of said transmitter.

8. The transmitter of claim 1, further comprising:

a first screw unit formed to be integrated or assembled with said printed circuit board; and

a second screw unit formed to be integrated or assembled with said optics module;

wherein said printed circuit board and said optics module are assembled using said first and second screw units.

9. The transmitter of claim 8, wherein

said first and second screw units are standardized whereby various optics modules having lenses of different sizes can be assembled with said printed circuit board.

10. The transmitter of claim 1, wherein

the light from said transmitter is eye-safe.

11. A receiver for Free Space Optical Communication comprising:

a photo-detecting module including a photo detector formed on a printed circuit board;

an optical receiver circuit, integrally formed on said printed circuit board, having a first terminal connected to said photo-detecting module for receiving input signals from said photo-detecting module, a second terminal for bias-in, and a third terminal for outputting electric signals generated by transforming the input signals from said photo-detecting module; and

an optics module formed to be assembled with said printed circuit board for receiving the light from the external free space and transmitting the received light to said photo detector of said photo-detecting module.

12. The receiver of claim 11, wherein

said photo-detecting module includes a preamplifier, formed on said printed circuit board and connected to said photo detector, for amplifying the signals obtained from said photo detector.

13. The receiver of claim 12, wherein said optical receiver circuit comprises:

a signal amplifier for amplifying the signals transferred from said photo-detecting module via said first terminal;

an automatic gain controller for controlling the gain of said signal amplifier;

a data recovery circuit for recovering data from the signals transferred from said signal amplifier; and

a clock generator for generating clock signals using the signals transferred from said signal amplifier and transferring said clock signals to said data recovery circuit.

14. The receiver of claim 11, wherein said optical receiver circuit comprises:

a preamplifier formed on said printed circuit board and connected to said photo detector for amplifying the signals obtained from said photo detector,

a signal amplifier for amplifying the signals transferred from said photo-detecting module via said first terminal;

an automatic gain controller for controlling the gain of said signal amplifier;

a data recovery circuit for recovering data from the signals transferred from said signal amplifier; and

a clock generator for generating clock signals using the signals transferred from said signal amplifier and transferring said clock signals to said data recovery circuit.

15. The receiver of claim 11, wherein

said optical receiver circuit has a fourth terminal for monitoring the magnitude of input signals at the outside of said optical receiver circuit.

16. The receiver of claim 15, further comprising

a display unit connected to said fourth terminal for displaying said magnitude of input signals.

17. The receiver of claim 15, wherein

said magnitude of input signals can be transferred to the base station at the outside of said receiver.

18. The receiver of claim 11, wherein said optics module comprises:

a lens; and

a lens holder being able to adjust the focal length of said lens.

19. The receiver of claim 18, wherein

said lens is an aspheric lens or a Fresnel lens.

20. The receiver of claim 11, further comprising:

a first screw unit formed to be integrated or assembled with said printed circuit board; and

a second screw unit formed to be integrated or assembled with said optics module;

wherein said printed circuit board and said optics module are assembled using said first and second screw units.

21. The receiver of claim 20, wherein

said first and second screw units are standardized whereby various optics modules having lenses of different sizes can be assembled with said printed circuit board.

22. A transceiver for Free Space Optical Communication comprising:

a first light source formed on a printed circuit board;

a first photo detector formed on said printed circuit board for detecting the light from said first light source;

a first current driver and controller circuit integrally formed on said printed circuit board having a first terminal for receiving input signals, a second terminal for bias-in, a third terminal connected to said first light source for outputting output signals to said first light source, and a fourth terminal connected to said first photo detector for receiving output control signals for controlling the output power of said first light source from said first photo detector;

a transmitting optics module formed to be assembled with said printed circuit board for receiving the light from said first light source and transmitting the received light to the external free space;

a photo-detecting module including a second photo detector formed on said printed circuit board;

a first optical receiver circuit integrally formed on said printed circuit board having a fifth terminal connected to said photo-detecting module for receiving input signals from said photo-detecting module, a sixth terminal for bias-in, and a seventh terminal for outputting electric signals generated by transforming the input signals from said photo-detecting module; and

a receiving optics module formed to be assembled with said printed circuit board for receiving the light from the external free space and transmitting the received light to said second photo detector of said photo-detecting module.

23. The transceiver of claim 22, wherein

said photo-detecting module includes a preamplifier formed on said printed circuit board and connected to said second photo detector for amplifying the signals obtained from said second photo detector.

24. The transceiver of claim 23, wherein said first optical receiver circuit comprises:

a signal amplifier for amplifying the signals transferred from said photo-detecting module via said fifth terminal;

an automatic gain controller for controlling the gain of said signal amplifier;

a data recovery circuit for recovering data from the signals transferred from said signal amplifier; and

a clock generator for generating clock signals using the signals transferred from said signal amplifier and transferring said clock signals to said data recovery circuit.

25. The transceiver of claim 22, wherein said first optical receiver circuit comprises:

a preamplifier for amplifying the signals obtained from said second photo detector of said photo-detecting module via said fifth terminal;

a signal amplifier for amplifying the signals transferred from said preamplifier;

an automatic gain controller for controlling the gain of said signal amplifier;

a data recovery circuit for recovering data from the signals transferred from said signal amplifier; and

a clock generator for generating clock signals using the signals transferred from said signal amplifier and transferring said clock signals to said data recovery circuit.

26. The transceiver of claim 22, wherein said first current driver and controller circuit comprises:

a light source driver circuit for driving said first light source by outputting pulse via said first terminal; and

an automatic output control circuit for controlling the output of said light source driver circuit according to the output control signals inputted via said fourth terminal.

27. The transceiver of claim 22, wherein

said first light source is a laser diode or a light emitting diode.

28. The transceiver of claim 22, wherein

said first light source and said first and second photo detectors are bonded to said printed circuit board using flip-chip bonding method.

29. The transceiver of claim 22, wherein said transmitting optics module comprises:

a first lens; and

a first lens holder being able to adjust the focal length of said first lens.

30. The transceiver of claim 29, wherein

said first lens is an aspheric lens or a Fresnel lens.

31. The transceiver of claim 22, wherein said receiving optics module comprises:

a second lens; and

a second lens holder being able to adjust the focal length of said second lens.

32. The transceiver of claim 31, wherein

said second lens is an aspheric lens or a Fresnel lens.

33. The transceiver of claim 22, wherein

said first optical receiver circuit comprises a eighth terminal for monitoring the magnitude of input signals at the outside of said first optical receiver circuit.

34. The transceiver of claim 33, further comprising

a display unit connected to said eighth terminal for displaying said magnitude of input signals.

35. The transceiver of claim 33,

wherein said magnitude of input signals can be transferred to the base station at the outside of said transceiver.

36. The transceiver of claim 22, further comprising:

a first screw unit formed to be integrated or assembled with said printed circuit board adjacent with the part of printed circuit board where said first light source, said first photo detector and said first current driver and controller circuit are formed;

a second screw unit formed to be integrated or assembled with said printed circuit board adjacent with the part of printed circuit board where said photo-detecting module and said first optical receiver circuit are formed;

a third screw unit formed to be integrated or assembled with said transmitting optics module; and

a fourth screw unit formed to be integrated or assembled with said receiving optics module;

wherein said printed circuit board and said transmitting optics module are assembled using said first and third screw units; and

wherein said printed circuit board and said receiving optics module are assembled using said second and fourth screw units.

37. The transceiver of claim 22, wherein

said transmitting optics module and said receiving optics module face to the same side.

38. The transceiver of claim 22, wherein

said transmitting optics module and said receiving optics module have the same configuration.

39. The transceiver of claim 22, wherein

said transmitting optics module and said receiving optics module have different configurations from each other.

40. The transceiver of claim 22, wherein

the light from said transmitting optics module is eye-safe.

41. The transceiver of claim 22, further comprising:

a second optical receiver circuit integrally formed on said printed circuit board and connected to the first terminal of said first current driver and controller circuit;

a third photo detector formed on said printed circuit board and connected to said second optical receiver circuit;

a second current driver and controller circuit integrally formed on said printed circuit board and connected to the seventh terminal of said first optical receiver circuit; and

a second light source formed on said printed circuit board, connected to said second current driver and controller circuit.

42. The transceiver of claim 41, further comprising:

a first optical fiber connected to said third photo detector;

a second optical fiber connected to said second light source; and

a media converter connected to said first and second optical fibers and having UTP (unshielded twisted-pair) port.

43. The transceiver of claim 41, wherein

said second light source is laser diode or light emitting diode.

44. The transceiver of claim 22, further comprising:

a media converter circuit formed on said printed circuit board, connected to said first terminal of said first current driver and controller circuit and said seventh terminal of said first optical receiver circuit and having UTP port.

45. A transponder for Free Space Optical Communication comprising:

a light source formed on a printed circuit board;

a first photo detector formed on said printed circuit board for detecting the light from said first light source;

a first current driver and controller circuit, integrally formed on said printed circuit board, having a first terminal for receiving input signals, a second terminal for bias-in, a third terminal connected to said first light source for outputting output signals to said first light source and a fourth terminal connected to said first photo detector for receiving output control signals for controlling the output of said first light source from said first photo detector;

a multiplexer, formed on said printed circuit board and connected to said first terminal of said current driver and controller circuit, for multiplexing input signals to output to said current driver and controller circuit via said first terminal;

a transmitting optics module formed to be assembled with said printed circuit board for receiving the light from said first light source and transmitting the received light to the external free space;

a photo-detecting module including a second photo detector formed on said printed circuit board;

a first optical receiver circuit, integrally formed on said printed circuit board, having a fifth terminal connected to said photo-detecting module for receiving input signals from said photo-detecting module, a sixth terminal for bias-in, and a seventh terminal for outputting electric signals generated by transforming the input signals from said photo-detecting module;

a demultiplexer, formed on said printed circuit board and connected to said seventh terminal of said optical receiver circuit, for receiving signals from said optical receiver circuit and outputting demultiplexed signals; and

a receiving optics module formed to be assembled with said printed circuit board for receiving the light from the external free space and transmitting the receiving light to said second photo detector of said photo-detecting module.

46. A transponder for Free Space Optical Communication comprising:

a photo-detecting module including a first photo detector formed on a first printed circuit board;

a first optical receiver circuit, integrally formed on said first printed circuit board, having a first terminal connected to said photo-detecting module for receiving input signals from said first photo-detecting module, a second terminal for bias-in, and a third terminal for outputting electric signals generated by transforming the input signals from said photo-detecting module;

a demultiplexer, formed on said first printed circuit board, having an input port connected to said third terminal of said optical receiver circuit for receiving signals from said optical receiver circuit, a drop port for distributing a part of demultiplexed signals, and an output port for outputting the rest of said demultiplexed signals;

a receiving optics module formed to be assembled with said first printed circuit board for receiving the light from the external free space and transmitting the received light to said first photo detector of said photo-detecting module;

a light source formed on a second printed circuit board;

a second photo detector formed on said second printed circuit board for detecting the light from said light source;

a current driver and controller circuit, integrally formed on said second printed circuit board, having a fourth terminal for receiving input signals, a fifth terminal for bias-in, a sixth terminal connected to said light source for outputting output signals to said light source and a seventh terminal connected to said second photo detector for receiving output control signals for controlling the output of said light source from said second photo detector;

a multiplexer, formed on said second printed circuit board, having an input port for receiving signals from said output port of said demultiplexer, an add port for receiving additional signals from the outside, and an output port for outputting multiplexed signal to said current driver and controller circuit; and

a transmitting optics module formed to be assembled with said second printed circuit board for receiving the light from said light source and transmitting the received light to the external free space.

47. A transponder for Free Space Optical Communication comprising:

a photo-detecting module including a first photo detector formed on a first printed circuit board;

an optical receiver circuit, integrally formed on said first printed circuit board, having a first terminal connected to said photo-detecting module for receiving input signals from said photo-detecting module, a second terminal for bias-in, and a third terminal for outputting electric signals generated by transforming the input signals from said photo-detecting module;

a receiving optics module formed to be assembled with said first printed circuit board for receiving the light from the external free space and transmitting the received light to said first photo detector of said photo-detecting module;

a demultiplexer, formed on a second printed circuit board, having an input port connected to said third terminal of said optical receiver circuit for receiving signals from said optical receiver circuit, a drop port for distributing a part of demultiplexed signals, and an output port for outputting the rest of said demultiplexed signals;

a multiplexer, formed on said second printed circuit board, having an input port for receiving signals from said output port of said demultiplexer, an add port for receiving additional signals from the outside, and an output port for outputting multiplexed signal to said current driver and controller circuit;

a light source formed on a third printed circuit board;

a second photo detector formed on said third printed circuit board for detecting the light from said light source;

a current driver and controller circuit, integrally formed on said third printed circuit board, having a fourth terminal for receiving input signals, a fifth terminal for bias-in, a third terminal connected to said light source for outputting output signals to said light source, and a seventh terminal connected to said second photo detector for receiving output control signals for controlling the output of said light source from said second photo detector; and

a transmitting optics module formed to be assembled with said printed circuit board for receiving the light from said light source and transmitting the received light to the external free space.

48. A transmitter for Free Space Optical Communication comprising:

a photo-optics module including a light source, a photo detector for detecting the light from said light source, and an optics module, formed to be integrated with said light source and said photo detector, for receiving the light from said light source and transmitting the received light to the external free space; and

a current driver and controller circuit, integrally formed on a printed circuit board, having a first terminal for receiving input signals, a second terminal for bias-in, a third terminal connected to said light source for outputting output signals to said light source, and a fourth terminal connected to said photo detector for receiving output control signals for controlling the output of said light source from said photo detector;

wherein said light source and said photo detector are connected to said third terminal and said fourth terminal respectively with flexible wires.

49. A receiver for Free Space Optical Communication comprising:

a photo-optics module including a photo-detecting module having a photo detector, and an optics module formed to be integrated with said photo-detecting module for receiving the light from the external free space and transmitting the light to said photo detector of said photo-detecting module; and

an optical receiver circuit, integrally formed on a printed circuit board, having a first terminal connected to said photo-detecting module for receiving input signals from said photo-detecting module, a second terminal for bias-in, and a third terminal for outputting electric signals generated by transforming the input signals from said photo-detecting module;

wherein said photo detector and said third terminal are connected with flexible wire.

50. A transceiver for Free Space Optical Communication comprising:

a transmitting photo-optics module including a light source, a first photo detector for detecting the light from said light source, and a transmitting optics module, formed to be integrated with said light source and said first photo detector, for receiving the light from said light source and transmitting the received light to the external free space;

a receiving photo-optics module including a photo-detecting module having a second photo detector, and a receiving optics module formed to be integrated with said photo-detecting module for receiving the light from the external free space and transmitting the received light to said second photo detector of said photo-detecting module;

a current driver and controller circuit, integrally formed on a printed circuit board, having a first terminal for receiving input signals, a second terminal for bias-in, a third terminal connected to said light source for outputting output signals to said light source, and a fourth terminal connected to said first photo detector for receiving output control signals for controlling the output of said light source from said first photo detector; and

an optical receiver circuit, integrally formed on said printed circuit board, having a fifth terminal connected to said photo-detecting module for receiving input signals from said photo-detecting module, a sixth terminal for bias-in, and a seventh terminal for outputting electric signals generated by transforming the input signal from said photo-detecting module;

wherein said light source and said first photo detector are connected to said third terminal and said fourth terminal respectively with flexible wires; and

wherein said second photo detector and said seventh terminal are connected with a flexible wire.