CN104601245A - Optical link capable of generating and transmitting radio frequency track angular momentum - Google Patents
Optical link capable of generating and transmitting radio frequency track angular momentum Download PDFInfo
- Publication number
- CN104601245A CN104601245A CN201410850243.4A CN201410850243A CN104601245A CN 104601245 A CN104601245 A CN 104601245A CN 201410850243 A CN201410850243 A CN 201410850243A CN 104601245 A CN104601245 A CN 104601245A
- Authority
- CN
- China
- Prior art keywords
- radio frequency
- angular momentum
- speculum
- link
- optical
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
Landscapes
- Optical Communication System (AREA)
Abstract
The invention discloses an optical link capable of generating and transmitting radio frequency track angular momentum. The diameter of existing radio frequency track angular momentum wave beams can obviously increase along with increase of transmission distance to result in receiving difficulty of a receiving end. The optical link capable of generating and transmitting radio frequency track angular momentum comprises an optical carrier radio frequency link and a free space optical link, wherein the optical carrier radio frequency link comprises a laser device, an optical amplifier and a photoelectric detector; radio frequency signals are modulated onto a beam emitted by the laser device through the an electro-optical modulator, and the beam enters the input end of the free space optical link; the beam output from the output end of the free space optical link is amplified through the optical amplifier and then enters the photoelectric detector to achieve recovery of the radio frequency signals. The optical link capable of generating and transmitting radio frequency track angular momentum integrates the characteristics that radio frequency track angular momentum wave beams are less prone to being interfered and optical frequency track angular momentum wave beams are less prone to divergence, improves the transmission quality of the track angular momentum wave beams, reduces distortion of the wave beams and accordingly improves the transmission efficiency of the wave beams.
Description
Technical field
The present invention relates to produce and carry orbital angular momentum wave beam field with transmission, particularly relate to and a kind ofly produce and transmit the optical link of radio frequency orbital angular momentum.
Background technology
Along with the increase of communication use amount, frequency spectrum resource reduces increasingly, and the capacity and the speed that improve communication system become matter of utmost importance.Electromagnetic angular momentum is divided into spin angular momentaum and orbital angular momentum, and spin angular momentaum corresponds to the polarized state of wave beam, and orbital angular momentum is not then also used.Therefore, orbital angular momentum is utilized to be a kind of new method improving spectrum efficiency.The electromagnetic wave carrying orbital angular momentum has spiral phase front, and this phase place is relevant with the mode number of attitude and orbital angular momentum.The different orbital angular momentum wave beam of mode number is completely orthogonal, so have reusability.When there being the wave beam of several different orbital angular momentum mode number to be combined on a wave beam by multiplexing, wherein each orbital angular momentum carries independent data, and so the capacity of communication system and spectrum efficiency just improve several times.In theory, the mode number of orbital angular momentum be can get infinitely-great.Therefore, the wave beam carrying orbital angular momentum is utilized to have good development prospect to the capacity and spectrum efficiency that improve communication system.
At present, the research for orbital angular momentum concentrates on optical frequency and radio-frequency range respectively.The production method of optical frequency orbital angular momentum wave beam mainly contains hologram, spiral phase plate etc., and the production method of radio frequency orbital angular momentum wave beam mainly contains spiral phase plate, excipient antenna, array antenna etc.These two kinds of orbital angular momentum wave beams have respective weak point.Because the wavelength of light wave is little, the phase place of optical frequency orbital angular momentum wave beam is easily subject to scattering and atmospheric turbulance impact, and wave beam is distorted.Radio frequency orbital angular momentum beam diameter significantly becomes large along with the increase of propagation distance, receiving terminal can be caused to receive difficulty.Both of these case is all unfavorable for the long-distance communications of orbital angular momentum wave beam.
Summary of the invention
The object of the present invention is to provide one to utilize light to carry radio-frequency technique, Free Space Optics, design optical link, thus produce and transmit the optical link carrying radio frequency orbital angular momentum wave beam.
Technical solution technical scheme that problem is taked of the present invention is:
The present invention includes light and carry radio frequency link and Free Space Optics link, described light carries radio frequency link and comprises laser, electrooptic modulator, image intensifer, photodetector; Radiofrequency signal is modulated on the light beam that laser sends by electrooptic modulator, this light beam freedom of entry space optical link input; Be amplified into through image intensifer the recovery that photodetector realizes radiofrequency signal from Free Space Optics link output light beam out; Described Free Space Optics link comprises first collimator, the second collimater, the first beam splitter, the second beam splitter, the first speculum and the second speculum; First collimator is as the input of Free Space Optics link, spatial light wave beam is transmitted on the first speculum by the first beam splitter, reflection spatial light wave beam through the first beam splitter reflection to the second beam splitter, be transmitted on the second speculum by the second beam splitter again, the spatial light wave beam of the second speculum reflection is by the second beam splitter reflection to the second collimater, and the second collimater is as the output of Free Space Optics link.
The first described speculum or the second speculum are different in the locus of different orientations folded light beam, make the light path of different orientations in the same space light beam different, thus change the phase place of radiofrequency signal.
The spatial light wave beam of the first described speculum reflection carries radio frequency orbital angular momentum signal.
The first described speculum is identical with the second mirror structure, shape complementarity; The light path of different orientations compensates by the second speculum, thus the phase place of the radiofrequency signal on light beam is reduced, and recovers primary signal.
The first described speculum and the second speculum are all step structures in the circumferential, difference in height between each ladder is much larger than optical wavelength, but with the wavelength of radiofrequency signal at the same order of magnitude, realize radio frequency signal with azimuthal phase shift by the difference in height changed between each ladder.The difference in height of two adjacent hierarchic structures is D, then the delay inequality Δ τ of adjacent steps structure reflects light beam is:
Wherein c is the light velocity in vacuum, the difference of the radiofrequency signal phase place caused
for:
Wherein f
rFfor the frequency of radiofrequency signal.Because the phase place of orbital angular momentum wave beam is with the periodically variable characteristic in azimuth, the change difference of adjacent hierarchic structure radio frequency signal phase meets:
Wherein l is the mode of orbital angular momentum, and N is the number of hierarchic structure in whole circumference.
Beneficial effect of the present invention: through light carry radio frequency theory analysis, Free Space Optics design optical link can produce the light beam of carrying radio frequency orbital angular momentum, the shortcoming that radio frequency orbital angular momentum wave beam diversity is large can be overcome, also can improve the problem that optical frequency orbital angular momentum wave beam is easily interfered.Therefore, this link can improve the efficiency of orbital angular momentum communication, can increase the distance of communication simultaneously.
Accompanying drawing explanation
Fig. 1 produces and transmits the optical link of radio frequency orbital angular momentum;
The speculum schematic diagram of Fig. 2 particular design;
Fig. 3 is the phase place schematic diagram of radiofrequency signal in reflection rear space light beam;
The end view of the speculum of Fig. 4 particular design;
Embodiment
Below in conjunction with accompanying drawing, the present invention is further described:
Produce and the general block diagram transmitting the optical link of radio frequency orbital angular momentum as shown in Figure 1.In figure, laser, electrooptic modulator, image intensifer, photodetector constitute light and carry radio frequency link, achieve the modulation of radiofrequency signal and the demodulation of radio frequency signal.Radiofrequency signal is modulated on the light beam that laser sends by electrooptic modulator, and radiofrequency signal is recovered by photodetector by receiving terminal.In Fig. 1, first collimator, the second collimater, the first beam splitter, the second beam splitter, the first speculum and the second speculum constitute Free Space Optics link, achieve generation and the compensation of radio frequency orbital angular momentum.Light beam is equivalent to through Free Space Optics link the modulation and demodulation achieving a radio frequency orbital angular momentum.The light beam transmitted between the first speculum and the second speculum is the light beam of carrying radio frequency orbital angular momentum.Transmit because radio frequency orbital angular momentum in this link is carried on spatial light wave beam, so overcome the larger shortcoming in radio frequency orbital angular momentum beam direction angle.Be simultaneously radio frequency orbital angular momentum due to what spatial light wave beam transmitted, corresponding circumferential phase place is changed to the phase place change of radio frequency.So small disturbance is relative to negligible radio frequency wavelength, also improve the shortcoming that optical frequency orbital angular momentum wave beam is easily interfered.
Fig. 2 is the structural representation of the speculum of particular design.The center of speculum is incided from collimater spatial light out.Can see that the speculum of particular design circumferentially has step structure, difference in height between each ladder is much larger than optical wavelength, but with the wavelength of radiofrequency signal at the same order of magnitude, realize radio frequency signal with azimuthal phase shift by the difference in height changed between each ladder.Fig. 3 is the phase place schematic diagram of radiofrequency signal in reflection rear space light beam.
Fig. 4 is the end view of particular design speculum.As figure, the difference in height of two adjacent hierarchic structures is D, then the delay inequality being irradiated to the light beam of the first half light beam and the latter half is
Wherein c is the light velocity in vacuum, and the difference of the radiofrequency signal phase place caused is
Wherein f
rFfor the frequency of radiofrequency signal.Because the phase place of orbital angular momentum wave beam is with the periodically variable characteristic in azimuth, the change difference of adjacent hierarchic structure radio frequency signal phase should meet
Wherein l is the mode of orbital angular momentum, and N is the number of whole circumferentially hierarchic structure.
According to above principle, Free Space Optics link with particular design speculum is added light inlet to be carried in radio frequency link, light beam between two pieces of particular design speculums will carry the radio frequency orbital angular momentum of phase vortex distribution, thus this hybrid optical link just can realize generation and the transmission of the light beam carrying radio frequency orbital angular momentum simultaneously.
Claims (1)
1. can produce and transmit the optical link of radio frequency orbital angular momentum, it is characterized in that: comprise light and carry radio frequency link and Free Space Optics link, described light carries radio frequency link and comprises laser, electrooptic modulator, image intensifer, photodetector; Radiofrequency signal is modulated on the light beam that laser sends by electrooptic modulator, this light beam freedom of entry space optical link input; Be amplified into through image intensifer the recovery that photodetector realizes radiofrequency signal from Free Space Optics link output light beam out; Described Free Space Optics link comprises first collimator, the second collimater, the first beam splitter, the second beam splitter, the first speculum and the second speculum; First collimator is as the input of Free Space Optics link, spatial light wave beam is transmitted on the first speculum by the first beam splitter, reflection spatial light wave beam through the first beam splitter reflection to the second beam splitter, be transmitted on the second speculum by the second beam splitter again, the spatial light wave beam of the second speculum reflection is by the second beam splitter reflection to the second collimater, and the second collimater is as the output of Free Space Optics link;
The first described speculum or the second speculum are different in the locus of different orientations folded light beam, make the light path of different orientations in the same space light beam different, thus change the phase place of radiofrequency signal;
The spatial light wave beam of the first described speculum reflection carries radio frequency orbital angular momentum signal;
The first described speculum is identical with the second mirror structure, shape complementarity; The light path of different orientations compensates by the second speculum, thus the phase place of the radiofrequency signal on light beam is reduced, and recovers primary signal;
The first described speculum and the second speculum are all step structures in the circumferential, difference in height between each ladder is much larger than optical wavelength, but with the wavelength of radiofrequency signal at the same order of magnitude, realize radio frequency signal with azimuthal phase shift by the difference in height changed between each ladder; The difference in height of two adjacent hierarchic structures is D, then the delay inequality Δ τ of adjacent steps structure reflects light beam is:
Wherein c is the light velocity in vacuum, the difference of the radiofrequency signal phase place caused
for:
Wherein f
rFfor the frequency of radiofrequency signal; Because the phase place of orbital angular momentum wave beam is with the periodically variable characteristic in azimuth, the change difference of adjacent hierarchic structure radio frequency signal phase meets:
Wherein l is the mode of orbital angular momentum, and N is the number of hierarchic structure in whole circumference.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201410850243.4A CN104601245B (en) | 2014-12-30 | 2014-12-30 | Optical link capable of generating and transmitting radio frequency track angular momentum |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201410850243.4A CN104601245B (en) | 2014-12-30 | 2014-12-30 | Optical link capable of generating and transmitting radio frequency track angular momentum |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN104601245A true CN104601245A (en) | 2015-05-06 |
| CN104601245B CN104601245B (en) | 2017-02-22 |
Family
ID=53126791
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201410850243.4A Active CN104601245B (en) | 2014-12-30 | 2014-12-30 | Optical link capable of generating and transmitting radio frequency track angular momentum |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN104601245B (en) |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN106352992A (en) * | 2016-09-06 | 2017-01-25 | 北京理工大学 | Self-adaptive correction method and system of wavefront-free and probe-free distortion vortex light beam |
| CN109768829A (en) * | 2019-01-09 | 2019-05-17 | 中南民族大学 | Atmospheric turbulance distortion compensating system and its method in orbital angular momentum optical transport |
| CN115117625A (en) * | 2022-07-05 | 2022-09-27 | 电子科技大学 | Method for generating phase-controllable OAM electromagnetic wave under random initial phase condition of phase-locked source |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101251655A (en) * | 2008-03-21 | 2008-08-27 | 北京理工大学 | Apparatus for implementing orbit angular momentum state super position and modulation |
| CN102148067A (en) * | 2011-01-27 | 2011-08-10 | 西北工业大学 | Device for generating rotary combined vortex light beam |
| CN103594918A (en) * | 2013-11-04 | 2014-02-19 | 华中科技大学 | Method and device for outputting hollow laser beam |
-
2014
- 2014-12-30 CN CN201410850243.4A patent/CN104601245B/en active Active
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101251655A (en) * | 2008-03-21 | 2008-08-27 | 北京理工大学 | Apparatus for implementing orbit angular momentum state super position and modulation |
| CN102148067A (en) * | 2011-01-27 | 2011-08-10 | 西北工业大学 | Device for generating rotary combined vortex light beam |
| CN103594918A (en) * | 2013-11-04 | 2014-02-19 | 华中科技大学 | Method and device for outputting hollow laser beam |
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN106352992A (en) * | 2016-09-06 | 2017-01-25 | 北京理工大学 | Self-adaptive correction method and system of wavefront-free and probe-free distortion vortex light beam |
| CN106352992B (en) * | 2016-09-06 | 2018-12-07 | 北京理工大学 | A kind of distortion vortex beams self-adapting correction method and system of the no wavefront without probe |
| CN109768829A (en) * | 2019-01-09 | 2019-05-17 | 中南民族大学 | Atmospheric turbulance distortion compensating system and its method in orbital angular momentum optical transport |
| CN115117625A (en) * | 2022-07-05 | 2022-09-27 | 电子科技大学 | Method for generating phase-controllable OAM electromagnetic wave under random initial phase condition of phase-locked source |
Also Published As
| Publication number | Publication date |
|---|---|
| CN104601245B (en) | 2017-02-22 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN107332618B (en) | A kind of access communications system of 5G-RoF center base station control wave beam forming | |
| CN101551517A (en) | Coherent laser communication system based on wavefront correction | |
| CN104954070A (en) | Self-adaptive optical fiber array type laser transmit-receive system used for spatial coherent light communication | |
| CN104393930A (en) | Device for improving spatially coherent light communication quality based on adaptive optical technology | |
| CN110221292B (en) | Microwave photon multiband radar imaging system and method | |
| Nagatsuma et al. | Practical considerations of terahertz communications for short distance applications | |
| US11750296B2 (en) | Optical communication link ranging | |
| CN104601245A (en) | Optical link capable of generating and transmitting radio frequency track angular momentum | |
| Sharma et al. | Modeling of 2.5 Gbps-intersatellite link (ISL) in inter-satellite optical wireless communication (IsOWC) system | |
| CN103532623B (en) | Photo-communication relay transmission method and system based on polarization shift keying modulation | |
| Niu et al. | Terrestrial coherent free-space optical communication systems | |
| Harada et al. | Adaptive beam divergence for expanding range of link distance in FSO with moving nodes toward 6G | |
| CN107819524B (en) | The light-operated transmission method of Multiple Superposition state radio frequency orbital angular momentum signal, system | |
| US20210036777A1 (en) | Optical communication network for pico satellites | |
| CN102004243B (en) | Optical bridge heterodyne receiving and complex value processing system for synthetic aperture laser imaging radar | |
| Sharma et al. | Performance analysis of inter-satellite optical wireless communication (Is-OWC) system by using channel diversity technique | |
| CN105553550A (en) | Optical wireless communication device and method applied to turbid media | |
| CN103856264A (en) | Extreme ultraviolet-ray space remote communication system | |
| CN113411126B (en) | Wireless optical communication atmospheric turbulence resistance method based on OAM mode hopping | |
| Panahi et al. | High speed laser communication network for satellite systems | |
| Singh et al. | Mode division multiplexing free space optics system with 3D hybrid modulation under dust and fog | |
| Yi et al. | Effects of phase fluctuation and intensity scintillation caused by weak atmospheric turbulence to BER employing distributed antenna array | |
| CN203800939U (en) | High-speed intermediate-infrared spatial laser communication system | |
| Serra et al. | Optical front-end for a quantum key distribution cubesat | |
| Panahi et al. | Optical laser cross-link in space-based systems used for satellite communications |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C06 | Publication | ||
| PB01 | Publication | ||
| C10 | Entry into substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant |