TWI634756B - 10 m/25 Gbps LiFi TRANSMISSION SYSTEM BASED ON A TWO-STAGE INJECTION-LOCKED 680 NM VCSEL TRANSMITTER - Google Patents

Abstract

We propose and verify a 10m/25Gbps wireless optical communication transmission system constructed by a second-order visible-injection mode-locking technology. This architecture can obtain good bit error rate and clear eye diagram, and can transmit data volume up to 25-Gbps and transmit 10 The distance of the meter. This technology allows wireless optical communication to gain the advantages of high data transmission, and accelerates the development of visible laser optical communication in the future.

Description

10m/25Gbps wireless optical communication transmission system constructed by visible light second-order injection mode-locking technology

The invention relates to a 10m/25Gbps wireless optical communication transmission system constructed by a visible light second-order injection mode-locking technology, in particular to a second-order injection mode-locking laser transmitter as a head end light source, with a low noise amplifier and clock and The data recovery circuit achieves high-speed data volume transmission.

The development of Free-space optical (FSO) communication provides megabit mobile applications. For more flexibility and speed data access, the key lies in the architectural design.

The common visible light communication system is constructed by transmitting light to the Light-Emitting Doide (LED). Although it has both illumination and transmission functions, it is limited by the LED bandwidth and the limited amount of material transmission.

In recent years, with the maturity of vertical cavity surface-emitting laser technology, high-power laser light increases the free-space transmission distance, and its bandwidth can reach about 5 GHz, which can be used as a high-speed data optical communication component for increasing data transmission. It is no longer sufficient. Although the problem of insufficient bandwidth can be improved by external modulation, the system cost is greatly increased and the system complexity is increased. However, the mature first-order injection-mode-locked laser effectively increases the frequency response, but also reaches the bottleneck of the bandwidth. .

In view of the prior art, an object of the present invention is to provide a 10m/25Gbps wireless optical communication transmission system constructed by a visible light second-order injection mode-locking technology. To achieve the above objective, the present invention provides a 10m/25Gbps wireless optical communication transmission system constructed by a visible light second-order injection mode-locking technology, comprising: a first vertical cavity surface-emitting laser; a first convex lens receiving the first vertical a laser beam of a cavity surface-emitting laser that converts visible light into a parallel beam; a second vertical cavity surface-emitting laser; and a second convex lens that receives a second vertical cavity surface-emitting laser The light beam converts the visible light into a parallel beam; the beam splitter has a first end connected to the first convex lens and a second end connected to the second convex lens, so that the parallel beam can be injected by the second vertical cavity surface type laser a first vertical cavity surface-emitting laser generates a first-order injection mode-locking and is emitted by a third end of the beam splitter; a first free-space optical isolator is coupled to the second end of the first beam splitter Between the second convex lenses, preventing reverse injection of the second vertical cavity surface-emitting laser; a third vertical cavity surface-emitting laser; and a third convex lens receiving the third vertical cavity surface-emitting laser Laser a light beam that converts visible light into a parallel beam; a second beam splitter having a first end connected to a third end of the first beam splitter and a second end connected to the third convex lens to enable visible light to be resolved by the third vertical beam The cavity surface type laser is injected into the first vertical cavity surface-emitting laser to generate a second-order injection mode-locking, and is emitted by the third end of a second beam splitter; a second free-space optical isolator is connected to the first Between the second end of the two beam splitter and the third convex lens, the reverse injection of the third vertical cavity surface type laser is prevented; and a spatial light modulator is connected to the third end of the second beam splitter. Convergence of parallel light to a point.

In other embodiments of the present invention, the 10m/25Gbps wireless optical communication transmission system constructed by the visible light second-order injection mode-locking technology may further include a photodetector and a low A noise amplifier, a clock and a data repeller, and a bit error rate analyzer. The second end of the photodetector is electrically connected to the low noise amplifier, and the clock and the data repeller are electrically connected to the low noise amplifier, and the telecommunications after the reply The number is sent to the bit error rate analyzer to evaluate the bit error rate performance and the corresponding constellation.

1,6,10‧‧‧Vertical cavity surface-emitting laser

2, 5, 9‧‧ ‧ convex lens

3, 7‧‧ ‧ beam splitter

4,8‧‧‧Free space optical isolator

11‧‧‧Space light modulator

12‧‧‧ Visible second-order injection mode-locking technology laser transmitter

13‧‧‧Photodetector

14‧‧‧Low noise amplifier

15‧‧‧clock and data restorer

16‧‧‧Bit rate analyzer

Figure 1 shows a laser transmitter with visible light second-order injection mode-locking technology.

Figure 2 is a 10m/25Gbps wireless device constructed by the visible light second-order injection mode-locking technology of the present invention. Schematic diagram of an optical communication transmission system.

Figure 3 is a comparison of frequency response.

Figure 4 shows the spectrum comparison chart.

Figure 5 is a comparison of bit error rate.

Figure 6 is a circuit diagram of the clock and data repeller.

Figure 7 is a comparison of the eye diagrams.

Please refer to FIG. 1 , which is a schematic diagram of a visible light second-order injection mode-locking technology, which is a schematic diagram of a 10 m/25 Gbps wireless optical communication transmission system laser transmitter 12 constructed as a transmitting end of the visible light second-order injection mode-locking technology of the present invention. Vertical cavity surface emitting laser (VCSEL) 1 and 6 and 10, convex lens 2 and 5 and 9, beam splitter 3 and 7, two free spaces Free-space optical isolator 4 and 8, a spatial light modulator 11.

Referring to FIG. 2, FIG. 2 is a 10m/25Gbps wireless optical communication transmission system constructed by the visible light second-order injection mode-locking technology according to the present invention. The utility model comprises a visible light second-order injection mode-locking technology laser transmitter 12, a photodiode 13, a low noise amplifier 14, a clock and data recovery, A bit error rate tester (BERT) 16.

Referring to FIG. 1 , a 10 m/25 Gbps wireless optical communication transmission system constructed by the visible light second-order injection mode-locking technique of FIG. 2 is illustrated, and the pseudo-random binary sequence signal is carried on the visible light second-order injection mode-locking technology laser transmitter 12 . The photodetector 13 converts the optical signal into a telecommunication signal. In order to reduce the noise during the electrical signal amplification process, the low noise amplifier 14 is used, and the clock and the data recovery device 15 are used to optimize the signal, and finally enter the bit error rate analyzer. 16 to evaluate the bit error rate performance and the corresponding constellation.

Claims (3)

A 10m/25Gbps wireless optical communication transmission system constructed by a visible light second-order injection mode-locking technology, comprising: a first vertical cavity surface-emitting laser; a first convex lens receiving a first vertical cavity surface-emitting laser a laser beam that converts visible light into a parallel beam; a second vertical cavity surface-emitting laser; and a second convex lens that receives a second vertical cavity surface-emitting laser beam to convert visible light into a a parallel beam; a beam splitter having a first end connected to the first convex lens and a second end connected to the second convex lens, wherein the parallel beam can be injected into the first vertical cavity by the second vertical cavity surface type laser The laser generates a first-order injection mode-locking and is emitted by the third end of the beam splitter; a first free-space optical isolator is connected between the second end of the first beam splitter and the second convex lens to prevent the reverse Injecting a second vertical cavity surface-type laser; a third vertical cavity surface-emitting laser; and a third convex lens receiving a laser beam of a third vertical cavity surface-emitting laser to convert visible light into One a parallel beam; a second beam splitter having a first end connected to a third end of a first beam splitter, The second end is connected to the third convex lens, so that the visible light can be injected into the first vertical cavity surface-emitting laser by the third vertical cavity surface-emitting laser, and the second-order injection mode-locking is generated, and the second beam splitter is a three-terminal exit; a second free-space optical isolator is connected between the second end of the second beam splitter and the third convex lens to prevent reverse injection of the third vertical cavity surface-emitting laser; a spatial light tone The transformer is connected to the third end of a second beam splitter to converge the parallel light to a point. The 10m/25Gbps wireless optical communication transmission system constructed by the visible light second-order injection mode-locking technology described in claim 1 further comprises a photodetector; and a bit error rate analyzer. The 10m/25Gbps wireless optical communication transmission system constructed by the visible light second-order injection mode-locking technology described in claim 2 further includes a low noise amplifier electrically connected to the photodetector; a clock and data recovery circuit electrically connected Low noise amplifier.