High dynamic receiver for free space optics application

• US 20040086283A1
• Filed: 10/30/2003
• Published: 05/06/2004
• Est. Priority Date: 10/31/2002
• Status: Active Grant

• Current Assignee: RPX Corporation
• Original Assignee: Alcatel SA (Nokia Corporation)
• Inventors: Paoli, Giovanni, Verbana, Gianfranco
• Granted Patent: US 7,269,360 B2
• Time in Patent Office: Days
• US Class Current: 398/212
• CPC Class Codes: H04B 10/1121 One-way transmission

Abstract

A receiver for an optics telecommunication system, the receiver comprises a first receiving device and means for focusing a received light beam carrying a signal towards such first receiving device. The receiver is characterized in that it further comprises at least a second receiving device and a beam splitter for splitting the focused light beam partially towards the first receiving device and partially towards the at least second receiving device. Tipically, the first receiver device is an APD diode while the second receiver device is a PIN diode. The telecommunication system is a Free Space Optics telecommunication system. A method is also described. The invention results in a high dynamic receiver. The dynamic of the invention receiver could be up to the sum of the dynamics of receivers provided with single receiving device (APD or PIN).

Claims

1. A receiver for an optics telecommunication system, the receiver comprising a first receiving device and means for focusing a received light beam carrying a signal towards the first receiving device, characterized in that it further comprises at least a second receiving device and a beam splitter for splitting the focused light beam partially towards the first receiving device and partially towards the at least second receiving device.

2. The receiver according to claim 1, characterized in that the beam splitter provides an asymmetric ratio in order to send different portions of the received signal power to the first and to the at least second receiving device.

3. The receiver according to any one of claims 1 or 2, characterized in that the first receiver device comprises an APD diode.

4. The receiver according to claim 1 or 2, characterized in that the at least second receiver device comprises a PIN diode.

5. The receiver according to claim 2, characterized in that the largest portion of the received signal is provided to the first receiving device.

6. The receiver according to claim 5, characterized in that the portion of the received signal which is provided to the first receiving device is between 85-98%, preferably around 90%, of the whole received power.

7. The receiver according to claim 1, characterized in that it further comprises a hitless switch block in turn comprising a switch logic block respondent to input power information from the first and the at least second receiving devices and to phase information from a phase comparator, the switch logic block driving a switch selecting a signal between the signal from the first receiving device and the signal from the at least second receiving device.

8. The receiver according to claim 1, characterized in that the optics telecommunication system is a Free Space Optics telecommunication system.

9. Method for providing high dynamic features in an Optics receiver, the receiver comprising a first receiving device and means for focusing a received light beam carrying a signal towards the first receiving device, characterized by the steps of providing at least a second receiving device and splitting the focused light beam partially towards the first receiving device and partially towards the at least second receiving device.

10. The method according to claim 9, characterized in that the step of beam splitting comprises the step of beam splitting according to an asymmetric ratio in order to send different portions of the received signal power to the first and to the at least second receiving device.

11. The method according to any one of claims 9 or 10, characterized in that the first receiver device comprises an APD diode and at least one second receiver device comprises a PIN diode.

12. The method according to any one of claims 9 or 10, characterized in that the step of beam splitting comprises providing the largest portion of the received signal to the first receiving device.

13. The method according to claim 12, characterized in that the portion of the received signal which is provided to the first receiving device is between 85-98%, preferably around 90%, of the whole received power.

14. The method according to claim 9, characterized by selecting a signal between the signal from the first receiving device and the signal from the at least one second receiving device according to phase information from a phase comparator and according to signal received power information.

15. The method according to claim 9, characterized in that the optics telecommunication system is a Free Space Optics telecommunication system.