Terahertz OAM generation system based on optical mixing and fusion optical communication system

Abstract

The invention discloses a terahertz OAM (Orbital Angular Momentum) generation system based on an optical mixing and fusion optical communication system. The terahertz OAM generation system includes two DFB (Distributed Feedback) lasers of which the frequency difference is in the terahertz band and which are used for generating optical communication wavelengths, a spatial light modulator which is used for modulating the orbital angular momentum of one channel of optical communication wavelength, a Mach-Zehnder modulator which is used for modulating the baseband electrical signal information ofthe other channel of optical communication wavelength, and a terahertz photoconductive antenna mixer which is used for beating the frequency of the combined optical signal to generate the terahertz band communication carriers of a modulated baseband signal carrying a certain order of orbital angular momentum. The frequency difference and phase difference transfer effects of the terahertz photoconductive antenna mixer are utilized to modulate the orbital angular momentum of one channel and the baseband electrical signal of the other channel without adding devices other than optical communication. The terahertz OAM generation system can be integrated with the current large-capacity optical communication system. By utilizing the frequency and phase transfer effects of photon mixing, the technical problems of OAM generation and channel multiplexing in the terahertz band can be solved.

Description

technical field

[0001] The invention relates to the technical field of optical fiber-wireless communication, in particular to the generation and channel multiplexing of orbital angular momentum (OAM) in the terahertz frequency band, and in particular to a terahertz OAM generation system based on optical mixing and fusion of optical communication systems. Background technique

[0002] At present, in terahertz communication systems, the generation of orbital angular momentum has been the bottleneck that constrains the experimental performance and practical application of terahertz OAM communication systems. Usually, the way to generate orbital angular momentum is to add reflective or transmissive spiral phase plate, holographic phase plate, or use metamaterials in the terahertz frequency band. However, these methods have great disadvantages: the production efficiency is low and they cannot be integrated with the communication system.

[0003] The methods for generating orbita...

Examples

Embodiment Construction

[0031] Such as figure 2 As shown, the specific working principle of the terahertz photoconductive antenna mixer is as follows:

[0032] The angular frequencies of the signals of the two optical communication wavelengths are ω + ,ω - ; The initial phases are One of them carries the orbital angular momentum of a certain order, and the other carries the modulated baseband electrical signal information. The orbital angular momentum is reflected in the spatial distribution information of the initial phase.

[0033] Assuming that the energy of the two signals is the same, the electric field fusion information of the beat frequency is as follows:

[0034]

[0035] The optical power incident on the terahertz photoconductive antenna mixer is:

[0036]

[0037] Since the high-frequency 2ω signal is not within the response range of the terahertz photoconductive antenna mixer, the corresponding power can be caused as follows:

[0038]

[0039] Among them, the DC component...

technical field

[0001] The invention relates to the technical field of optical fiber-wireless communication, in particular to the generation and channel multiplexing of orbital angular momentum (OAM) in the terahertz frequency band, and in particular to a terahertz OAM generation system based on optical mixing and fusion of optical communication systems. Background technique

[0002] At present, in terahertz communication systems, the generation of orbital angular momentum has been the bottleneck that constrains the experimental performance and practical application of terahertz OAM communication systems. Usually, the way to generate orbital angular momentum is to add reflective or transmissive spiral phase plate, holographic phase plate, or use metamaterials in the terahertz frequency band. However, these methods have great disadvantages: the production efficiency is low and they cannot be integrated with the communication system.

[0003] The methods for generating orbita...

Examples

Embodiment Construction

[0031] Such as figure 2 As shown, the specific working principle of the terahertz photoconductive antenna mixer is as follows:

[0032] The angular frequencies of the signals of the two optical communication wavelengths are ω + ,ω - ; The initial phases are One of them carries the orbital angular momentum of a certain order, and the other carries the modulated baseband electrical signal information. The orbital angular momentum is reflected in the spatial distribution information of the initial phase.

[0033] Assuming that the energy of the two signals is the same, the electric field fusion information of the beat frequency is as follows:

[0034]

[0035] The optical power incident on the terahertz photoconductive antenna mixer is:

[0036]

[0037] Since the high-frequency 2ω signal is not within the response range of the terahertz photoconductive antenna mixer, the corresponding power can be caused as follows:

[0038]

[0039] Among them, the DC component...

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