CN1479476A - Production method f twittering pulse - Google Patents
Production method f twittering pulse Download PDFInfo
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- CN1479476A CN1479476A CNA021292027A CN02129202A CN1479476A CN 1479476 A CN1479476 A CN 1479476A CN A021292027 A CNA021292027 A CN A021292027A CN 02129202 A CN02129202 A CN 02129202A CN 1479476 A CN1479476 A CN 1479476A
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- light intensity
- intensity modulator
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- Optical Modulation, Optical Deflection, Nonlinear Optics, Optical Demodulation, Optical Logic Elements (AREA)
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Abstract
Continuous laser signal from light emission module is input to a light intensity modulator. A radio frequency signal modulates the said laser signal so as to obtain non-return to zero or return to zero light intensity pulsed signal with radio frequency information being carried. The characters are that adjusting or changing DC bias operating point of light intensity modulator in light emission module makes output of light intensity pulsed signal generate chatter as well as change spectral distribution of light signal output. The invention possesses features of simple procedure, eliminating phase modulator used in traditional method, without need of synchronous light pulsed signal. The invention is applicable to long-distance or ultra long TDM and/or WDM optical fiber transmission system.
Description
Affiliated field
The present invention relates to the production method of a kind of warbling (chirp) pulse, exactly, relate to a kind of in light emission module additive phase modulator no longer, the method of the direct current biasing working point of the light intensity modulator by adjust producing non-return-to-zero or return-to-zero optical signals pulse, come phase adjusted is carried out in the luminous intensity pulse, produce frequency chirp, thereby change the method for light signal spectral distribution.Belong to the fiber optic transmission system technical field.
Background technology
In the digital light transmission system, normally represent digital signal " 0 " or " 1 " with the intensity size of the light intensity signal in the time slot.But the light intensity pulse can be subjected to the damage of chromatic dispersion, nonlinear effect in the process of optical fiber and the transmission of other function elements.The spectrum distribution of light intensity signal also can be to the transmission characteristic of light pulse in fibre system, the result and the degree generation influence in various degree that influenced by chromatic dispersion and nonlinear effect and interaction thereof.Now, people are normally by adding that to the luminous intensity pulse signal suitable frequency chirp adjusts its frequency spectrum, are used to suppress the nonlinear effect between signal light intensity and optical fiber and the optical device.So in order to realize two-forty (40Gbit/s and more than) and long distance or over distance optical transmission, people have begun the research to the various pulse code types modulated of warbling, and begin to enter commercialization gradually.At present, the implementation method of traditional chirped pulse signal is to adopt an additional phase-modulator on the basis of original basic light emission module, to the non-return-to-zero (NRZ that has produced, Non-Return-to-Zero) or (RZ that makes zero, Return-to-Zero) light intensity pulse signal carries out phase modulated again, thereby make light intensity signal produce frequency chirp, its spectrum changes.The production process of this chirped pulse signal is as shown in Figure 1: the continuous laser signal or the pulsed optical signals of emission are input in the intensity modulator, number drive with electrical data signal, just can obtain having loaded the non-return-to-zero (NRZ) of transmitting data information or the light intensity pulse signal of make zero (RZ); Then, this light intensity signal is imported into phase-modulator, utilizes the suitable phase place signal of telecommunication to drive in phase-modulator again, and is promptly exportable to transmitting favourable chirped pulse signal, i.e. frequency modulation on pulse signal.Because this conventional method need increase a phase-modulator on the basis of original light emission module, make equipment cost increase naturally; And realizing technical drive signal and the synchronous problem of light pulse data-signal that how to make phase-modulator that also exist, promptly will guaranteeing warbles is loaded on the correct position, and it is higher to specification requirement to make operation go up.For this reason, the insider is in the method for exploring and seeking to produce how more simply, easily the chirped pulse signal.
Summary of the invention
The production method that the purpose of this invention is to provide a kind of chirped pulse, this method is not used phase-modulator, and implementation procedure is simple, easy to operate.
The object of the present invention is achieved like this: a kind of production method of chirped pulse, this method is that the continuous laser signal that will launch in the light emission module is input in the light intensity modulator, with radiofrequency signal it is modulated driving, with the luminous intensity pulse signal that obtains having loaded the non-return-to-zero of radio-frequency information or make zero; It is characterized in that: adjust or change the direct current biasing working point of light intensity modulator in the light emission module, the luminous intensity pulse signal generation of output is warbled, change the spectrum distribution of its output light signal simultaneously.
By adjusting or change the position of the direct current biasing working point of described light intensity modulator, regulate the response interval of determining this intensity modulator, warbling of control loaded makes the optical signal spectrum of its output produce different changes.
In the one-period of light intensity modulator response curve, promptly interval (V
0, V
2π] regulate in the scope its direct current biasing working point is set, the phase place of the light pulse signal of output is changed, produce and load the light pulse signal of warbling.
Light intensity modulator in the described light emission module can use direct modulation or electric absorption or interfere type.
Described radiofrequency signal can be used the signal of telecommunication of clock signal or data-signal or other purposes.
Described light intensity modulator can be provided with multistage, and adjustment and change be the direct current biasing working point of any one-level light intensity modulator wherein, all can change the spectrum distribution of output light signal.
The present invention is a kind of production method of chirped pulse, this method is an additive phase modulator no longer in light emission module, by adjusting the direct current biasing working point of the light intensity modulator that produces non-return-to-zero or return-to-zero optical signals pulse, come the luminous intensity pulse is carried out phase adjusted and produced frequency chirp, thus the spectral distribution of change light signal.This method implementation procedure is simple, has abandoned the phase-modulator in the conventional method, has saved equipment cost; Also need not to guarantee the drive signal of this phase-modulator and light pulse signal synchronously, easy to operate, have good popularization and application prospect, be specially adapted to the fiber optic transmission system of long distance or extra long distance time division multiplexing and/or wavelength division multiplexing.
Description of drawings
Fig. 1 is the schematic diagram of traditional chirped pulse signal production process.
Fig. 2 (A), (B) are respectively the block diagram and the function realization figure of the intensity modulator in the inventive method.
Fig. 3 (A), (B) are respectively the production process schematic diagrames of no NRZ chirped pulse and NRZ chirped pulse.
Fig. 4 (A), (B) are respectively the spectrograms of the chirped pulse signal of the described two kinds of methods generation of Fig. 3 (A), (B).
Embodiment
The present invention is a kind of production method of chirped pulse, this method is that the continuous laser signal that will launch in the light emission module is input in the light intensity modulator, with radiofrequency signal it is modulated driving, with the non-return-to-zero (NRZ) that obtains having loaded radio-frequency information or the luminous intensity pulse signal of make zero (RZ); By adjusting or change the direct current biasing working point of light intensity modulator in the light emission module, the luminous intensity pulse signal generation of output is warbled, change the spectrum distribution of its output light signal simultaneously.The inventive method is used for time division multiplexing optical transmission system and/or Wave division multiplexing optical transmission system, and the transmission rate of this optical transmission system can be any numerical value, promptly comprises 2.5Gbit/s, 10Gbit/s, 40Gbit/s or higher rate.
Referring to Fig. 2, wherein Fig. 2 (a) represents that the input signal of this light intensity modulator is that the modulation that is subjected to radiofrequency signal is exported afterwards.Same input signal, because the rf modulated signal intensity difference of its loading, the output response of this modulator is also different.By adjusting or change the position of the direct current biasing working point of described light intensity modulator, can regulate the response interval of determining this intensity modulator, make the light signal of its output be loaded with certain warbling, change its spectral distribution simultaneously.The position of each light intensity modulator direct current biasing working point is according to actual conditions, (comprises its starting point V at the one-period of this light intensity modulator response curve
0With terminal point V
2π) in the scope, promptly interval (V
0, V
2π] regulate in the scope its direct current biasing working point is set.For example in Fig. 2 (b), its direct current biasing working point is arranged on V pi/2 place (referring to Fig. 2 (b)), and in the appropriate response interval of this intensity modulator, radio-frequency information is loaded on the output signal.Radiofrequency signal described here can be used the signal of telecommunication of clock signal or data-signal or other purposes.Method of the present invention is used to produce and makes zero and/or the light emission module of the luminous intensity pulse signal of nonreturn to zero code, and the light intensity modulator in the light emission module can use direct modulation or electric absorption or interfere type.
Produce the process schematic diagram that the NRZ light pulse is exported referring to one shown in Fig. 3 (a): at first, continuous laser is sent in the first order intensity modulator, this moment, its direct current biasing working point was located at V pi/2 place, and drive this intensity modulator with continuous clock signal, make it to export the continuous light pulse signal; This continuous light pulse signal is imported in the intensity modulator of the second level again, and this grade intensity modulator is to modulate with data-signal, equally its direct current biasing working point is located at V pi/2 place, consequently exports the pulse of NRZ optical information stream.Warble and make zero process that light pulse produces then shown in Fig. 3 (b), both production processes are basic identical, difference is the direct current biasing working point of first order intensity modulator to be regulated be arranged on V π place to some extent, because saltus step can take place the phase place of adjacent light pulse signal like this, have the NRZ continuous light pulse signal of warbling thereby produce.After this, this optical pulse stream signal is admitted in the second level intensity modulator of modulating with data-signal again, and output at last has the NRZ optical information signal pulse stream of warbling.In being provided with the light emission module of multistage light intensity modulator, adjustment and change be the direct current biasing working point of any one-level light intensity modulator wherein, all can change the spectrum distribution of output light signal.
Referring to Fig. 4 (a) and (b) Fig. 3 (a) direct current biasing working point shown in respectively be arranged on V pi/2 place and Fig. 3 (b) direct current biasing working point is arranged on the flashlight spectrogram that the two kinds of methods in V π place obtain, as seen the direct current biasing point is placed on V π place, signal spectrum carrier wave is suppressed, and-15dB spectrum is pressed narrow.The order of above two-stage modulator can change, and wherein the direct current biasing working point of one-level can change it as required arbitrarily, and can regulate the spectral shape of output signal by the position of adjustment and change direct current biasing working point.Only need equally also to be suitable for the inventive method under the situation of one-level intensity modulated in the nonreturn to zero code modulation.
Claims (6)
1, a kind of production method of chirped pulse, this method is that the continuous laser signal that will launch in the light emission module is input in the light intensity modulator, with radiofrequency signal it is modulated driving, with the luminous intensity pulse signal that obtains having loaded the non-return-to-zero of radio-frequency information or make zero; It is characterized in that: adjust or change the direct current biasing working point of light intensity modulator in the light emission module, the luminous intensity pulse signal generation of output is warbled, change the spectrum distribution of its output light signal simultaneously.
2, the production method of chirped pulse according to claim 1, it is characterized in that: by adjusting or change the position of the direct current biasing working point of described light intensity modulator, regulate the response interval of determining this intensity modulator, warbling of control loaded makes the optical signal spectrum of its output produce different changes.
3, the production method of chirped pulse according to claim 1 and 2 is characterized in that: in the one-period of light intensity modulator response curve, and promptly interval (V
0, V
2π] regulate in the scope its direct current biasing working point is set, the phase place of the light pulse signal of output is changed, produce and load the light pulse signal of warbling.
4, the production method of chirped pulse according to claim 1 is characterized in that: the light intensity modulator in the described light emission module can use direct modulation or electric absorption or interfere type.
5, the production method of chirped pulse according to claim 1 is characterized in that: described radiofrequency signal can be used the signal of telecommunication of clock signal or data-signal or other purposes.
6, the production method of chirped pulse according to claim 1, it is characterized in that: described light intensity modulator can be provided with multistage, adjustment and change be the direct current biasing working point of any one-level light intensity modulator wherein, all can change the spectrum distribution of output light signal.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CNA021292027A CN1479476A (en) | 2002-08-27 | 2002-08-27 | Production method f twittering pulse |
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CNA021292027A CN1479476A (en) | 2002-08-27 | 2002-08-27 | Production method f twittering pulse |
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| CN1479476A true CN1479476A (en) | 2004-03-03 |
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Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102047071B (en) * | 2008-05-28 | 2012-09-05 | 莱卡地球系统公开股份有限公司 | Interferometric distance-measuring method with delayed chirp signal and such an apparatus |
| CN103346854A (en) * | 2013-07-09 | 2013-10-09 | 清华大学 | Optical time-diversion multiplexing device based on aperture limited time lens |
| CN111609919A (en) * | 2020-06-09 | 2020-09-01 | 重庆大学 | Optical Fiber Distributed Vibration and Loss Simultaneous Detection System |
-
2002
- 2002-08-27 CN CNA021292027A patent/CN1479476A/en active Pending
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102047071B (en) * | 2008-05-28 | 2012-09-05 | 莱卡地球系统公开股份有限公司 | Interferometric distance-measuring method with delayed chirp signal and such an apparatus |
| CN103346854A (en) * | 2013-07-09 | 2013-10-09 | 清华大学 | Optical time-diversion multiplexing device based on aperture limited time lens |
| CN103346854B (en) * | 2013-07-09 | 2016-01-20 | 清华大学 | A kind of light time decomposition multiplex device based on aperture restricted time lens |
| CN111609919A (en) * | 2020-06-09 | 2020-09-01 | 重庆大学 | Optical Fiber Distributed Vibration and Loss Simultaneous Detection System |
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