JP4027858B2 - Dispersion compensation method and apparatus for ultrashort optical pulse signal - Google Patents

Description

  The present invention relates to a method and apparatus for compensating for dispersion generated in an optical fiber transmission line in an optical signal transmission system, and more particularly, to represent a temporal change of each wavelength included in an optical pulse. In a technology that uses only light in a two-dimensional spectrogram, directly compensates for dispersion with a two-dimensional dispersion compensation device, converts it to an ultrashort optical pulse again, and transmits it to an ultrashort optical pulse with unknown dispersion, The present invention relates to a technique that can perform dispersion compensation instantaneously and completely passively.

  With the recent development of information communication networks using optical fibers, high-capacity and high-speed communication has become familiar in our lives. Recently, real-time distribution of movies has become possible using this high-capacity, high-speed communication. However, in order to enable high-speed Internet communication that does not feel stress, and multimedia communication including fields such as distance distribution and telemedicine from movie distribution, further increase in communication capacity is required. For example, around 2010, it is expected that an ultrahigh-speed backbone network of 150 Mbps at home, 10 Gbps at the office, and Tbps to Pbps levels in the trunk line system will be required.

  In order to increase the communication capacity, it is necessary to improve the signal density and the modulation speed. Therefore, in order to improve the signal density, researches such as optical time division multiplexing (OTDM) and wavelength division multiplexing (WDM) have been actively conducted. In addition, research using an optical-optical switch has been conducted to improve the modulation speed. However, in order to increase the communication capacity simply by advancing these technologies, enormous devices and costs are required, and precise control becomes very difficult.

  Therefore, as a breakthrough for increasing communication capacity, a technique using an ultrashort optical pulse having both OTDM and WDM properties as a light source is disclosed in Non-Patent Document 1 below. Since the ultrashort optical pulse is formed by superimposing wavelength components having a wide band, it has an enormous wavelength resource, and since its time width is very short, it is possible to form a high-density time signal.

  However, since an ultrashort optical pulse is formed from a wavelength component having a wide band, a new problem called “dispersion” occurs when propagating through a transmission line such as an optical fiber. This indicates a phenomenon in which the speed of propagation varies depending on the wavelength in the optical fiber, and therefore, when traveling a certain distance, the arrival time differs for each wavelength. In other words, in the case of an ultra-short optical pulse that is not dispersed, all the wavelength components included are aligned at the central reference time, but in the case of an ultra-short optical pulse that is dispersed, each wavelength shifts from the reference time, and a certain wavelength component Is in a state where a certain wavelength component exists after the reference time before the reference time.

  As a result, the signal waveform of the ultrashort light pulse is destroyed, and long-distance transmission becomes difficult. Moreover, the influence of this dispersion becomes a problem not only in the case of using an ultrashort optical pulse but also in a wavelength-multiplexed signal. In this case, a time shift occurs between the respective wavelength signals, which causes a timing error.

  Therefore, a “dispersion compensation” system has been used to restore the time lag of the signal waveform of the ultrashort optical pulse and the wavelength multiplexed signal. In the dispersion compensation system, an operation for correcting a time shift of each wavelength component and restoring the pulse waveform of the ultrashort optical pulse is performed.

  In a general dispersion compensation system, a dispersion element such as a diffraction grating pair or a prism pair is used. Then, the optical pulse is decomposed for each wavelength, necessary time compensation is performed for each wavelength, and dispersion compensation is performed by returning to the optical pulse signal again.

  In these conventional systems, the path through which the optical pulse passes is known, and the dispersion compensation is used when the dispersion amount is known in advance or when there is no need to change the dispersion compensation amount at high speed. Can be done.

Note that Patent Documents 1 to 4 are disclosed as prior art relating to conversion of ultrashort optical pulse signals and signal processing as follows. Further, Patent Document 5 is disclosed as a device that compensates for chromatic dispersion of light generated when passing through an optical fiber.
JP 11-46304 A (page 3-5, FIG. 1) Japanese Patent No. 3018173 (page 2-3, Fig. 1) Japanese Patent Laid-Open No. 2000-275589 (page 3-4, FIG. 1) JP 2002-72270 A (page 3-4, FIG. 1) Japanese translation of PCT publication No. 2002-514323 (FIG. 13) T.A. Morioka, K .; Mori, and M.M. Saruwatari, “More than 100-wavelength-channel picosecond optical pulse generation, single laser source using supercontinuum in optical fibers. Lett. 29,862-864 (1993)

  However, in the conventional technique described above, for an optical pulse signal whose path through which an optical pulse passes is unknown and the amount of dispersion is unknown, it is necessary to measure the amount of dispersion first, and to record the optical pulse signal. It was impossible to perform instantaneous dispersion compensation because of mechanical and mechanical operations.

  In view of the above situation, the present invention provides a method and apparatus for performing real-time dispersion compensation in which processing is completely passive without using mechanical and active operations for an optical pulse signal whose amount of dispersion is unknown. For the purpose.

In order to achieve the above object, the present invention provides
[1] An ultrashort optical pulse signal is developed using only light in a two-dimensional spatial light spectrogram representing temporal changes of each wavelength included in the ultrashort optical pulse signal, and the two-dimensional spatial optical spectrogram is two-dimensionally displayed. A dispersion compensation method for an ultrashort optical pulse signal that is directly modulated by a modulation device and converted again to an optical pulse signal, wherein a trigger pulse spatially separated from the signal light is converted into an optical-optical switch by a first cylindrical lens. Is incident on a nonlinear optical crystal, and the signal light is spatially separated and cut out in the X-axis direction. The cut-out signal light is collimated by a second cylindrical lens, and then dispersed in a Y-axis direction. The optical pulse signal decomposed and dispersed for each wavelength is compensated completely and instantaneously without using an active optical device.

  [2] The dispersion compensation method for an ultrashort optical pulse signal according to [1], wherein the ultrashort optical pulse signal is an ultrashort optical pulse signal whose amount of dispersion is unknown.

  [3] The dispersion compensation method for an ultrashort optical pulse signal according to [1], wherein the ultrashort optical pulse signal is an ultrashort optical pulse signal having a multiplexed wavelength.

  [4] In the dispersion compensation method for an ultrashort optical pulse signal described in [1] above, a wavelength component having an arbitrary time delay in the dispersed ultrashort optical pulse signal is automatically developed at a predetermined spatial position. It is characterized by that.

  [5] The dispersion compensation method for ultrashort optical pulse signals according to [1] above, wherein the trigger pulse is a discrete triple pulse.

  [6] The dispersion compensation method for ultrashort optical pulse signals according to [1] above, wherein the trigger pulse is a continuous pulse train.

[ 7 ] In the dispersion compensation method for ultrashort optical pulse signals, the spatial distribution developed in the above [4] can be compensated for dispersion by a passive optical element.

[ 8 ] The dispersion compensation method for ultrashort optical pulse signals according to [ 7 ] above, wherein a diffractive cylindrical lens pair is used as the passive optical element .

[ 9 ] In the dispersion compensation method for ultrashort optical pulse signals according to [ 8 ] above, the amount of dispersion compensation can be made variable by moving the diffractive cylindrical lens pair electrically, magnetically, and mechanically. It is characterized by.

[ 10 ] An ultrashort optical pulse signal is expanded using only light in a two-dimensional space spectrogram representing temporal changes in each wavelength included in the ultrashort optical pulse signal, and the two-dimensional spatial spectrogram is converted into a two-dimensional modulation device. Is a dispersion compensation device for an ultrashort optical pulse signal that is directly modulated by the optical signal and converted again into an ultrashort optical pulse signal, wherein a trigger pulse spatially separated from the signal light is converted into an optical-optical switch by a first cylindrical lens. Means for making it incident on a non-linear optical crystal that operates as follows, the incident signal light and the trigger pulse are extracted by spatially separating the signal light in the X-axis direction, and the extracted signal light is collimated by a second cylindrical lens After that, the means for resolving each wavelength in the Y-axis direction using a dispersive element and the dispersed ultrashort optical pulse signal without using an active optical device Characterized in that it comprises means for full passively compensated.

[ 11 ] The dispersion compensator for an ultrashort optical pulse signal according to [ 10 ], further comprising means for instantaneously compensating an ultrashort optical pulse signal with an unknown dispersion amount without using an active optical device. And

[ 12 ] The dispersion compensator for an ultrashort optical pulse signal according to [ 10 ], further comprising means for passively compensating for dispersion of the wavelength-multiplexed ultrashort optical pulse signal.

[ 13 ] In the dispersion compensator for ultrashort optical pulse signals described in [ 10 ] above, the wavelength component having an arbitrary time delay in the dispersed ultrashort optical pulse signal is automatically developed at a predetermined spatial position. Means are provided.

  The present invention makes it possible to perform real-time dispersion compensation in which the processing is completely passive without using any mechanical or active operation of the dispersed optical pulse signal.

  In particular, it is effective for high-speed and large-capacity transmission using ultrashort light pulses.

  An optical pulse signal is developed using only light in a two-dimensional spatial light spectrogram representing temporal changes of each wavelength included in the optical pulse signal, and the two-dimensional spatial light spectrogram is directly modulated by a two-dimensional modulation device. In dispersion compensation of an ultrashort optical pulse signal that is converted back to an optical pulse signal, the dispersed optical pulse signal is compensated for all passively and instantaneously using only passive optical elements without using an active optical device.

  Embodiments of the present invention will be described below with reference to the drawings.

  In the present invention, in order to perform dispersion compensation for an optical pulse whose amount of dispersion is unknown, first, the time signal component of the optical pulse is developed as a spatial signal component. That is, the time waveform of the optical pulse signal is developed along one axis on the space plane. The developed spatial signal is decomposed for each wavelength component included along another axis on the spatial plane. That is, a certain point on the developed two-dimensional spatial distribution corresponds to a certain wavelength component at a certain time in the optical pulse signal. This developed two-dimensional spatial distribution is called an optical spectrogram. At this time, the time waveform is developed along one axis on the above-described space plane, but the spatial distribution is also on the reference plane that actually becomes the reference time by the amount corresponding to the amount of time deviation along the direction. On the other hand, the distribution is shifted in time. Since each wavelength component in the optical pulse shifted from the reference time is automatically mapped to a spatial position corresponding to the amount of time shift, time compensation is performed by arranging an element for time compensation at that position. Is possible. Therefore, it becomes possible to perform real-time dispersion compensation without using any mechanical / active operation and making the processing completely passive.

  Details will be described below.

  The dispersion compensation system according to the present invention is mainly composed of three subsystems as described below.

  FIG. 1 is a schematic diagram showing an outline of dispersion compensation of an ultrashort optical pulse signal according to the present invention.

  In the first sub-system 101, the ultrashort light pulse signals 102 and 102 'are expanded into a two-dimensional spatial light spectrogram 112. Here, 104 is an optical fiber transmission path through which the ultrashort optical pulse signal 102 is propagated, and 105 is an optical system.

  Here, an ultrashort optical pulse signal 102 as a transmission signal is developed into a time-wavelength two-dimensional spatial light spectrogram 112. That is, it develops on a plane having time as the X axis and wavelength as the Y axis. The amount shifted from the center of the X axis is the amount of time shift, and is automatically mapped to the spatial position corresponding to the amount of time shift.

  The second subsystem 111 spatially performs time compensation required for each wavelength component.

  That is, (a) a two-dimensional optical spectrogram 112 developed on a plane having time as the X axis and wavelength as the Y axis, (b) a passive optical element that performs time compensation (here, a phase compensation plate described later is shown). (This may be a diffractive cylindrical lens pair to be described later) 113, thereby generating (c) time-compensated distribution spectrogram 114.

  In the third subsystem 121, the time-compensated distribution spectrogram 114 is converted again into the ultrashort optical pulse signal 123. Here, 124 is an optical system, and 125 is an optical fiber transmission path through which ultrashort optical pulse signals 123 and 123 'are propagated.

Hereinafter, embodiments of the three subsystems and a dispersion compensation method will be described in detail.
[First subsystem]
In the first subsystem 101, the time waveform of each wavelength component included in the ultrashort optical pulse signal 102 is developed as a spatial distribution along the horizontal direction (X-axis direction), and the vertical direction ( The optical spectrogram 112 of the ultrashort optical pulse signal 102 is obtained by arranging in the Y-axis direction).

FIG. 2 is a conceptual diagram thereof. The central reference time is determined by the trigger signal used, and the wavelength component within the reference time (t = 0) in the ultrashort optical pulse signal 102 is the position of (x = 0) on the two-dimensional spatial distribution plane. The other components are expanded on the Y axis. For example, the wavelength component (t = −τ ₁ ) is at the position (x = −x ₁ ), and the wavelength component (t = τ ₁ ) is (x = x ₁ ). It is developed along the Y-axis direction of the position. Further, the distribution existing at a position on (x = −x ₁ ) of the developed two-dimensional spatial distribution corresponds to z ₁ = −τ ₁ × c with reference to the plane including the X axis and the Y axis. On the other hand, a distribution that is delayed by an amount corresponding to a position on (x = x ₁ ) is developed as a distribution having a spatiotemporal profile advanced by an amount corresponding to z ₁ = τ ₁ × c.

  FIG. 3 is a schematic diagram of an optical system for realizing this signal conversion.

Here, in order to simplify the explanation, triple pulses cut out at arbitrary three times out of the dispersed ultrashort optical pulse signals 102 are used as signals. The respective pulses are designated as SP1, SP2, and SP3. On the other hand, triple pulses are also prepared as trigger pulses, and the respective trigger pulses are designated as TP1, TP2, and TP3. At this time, TP1, TP2, and TP3 are temporally synchronized with SP1, SP2, and SP3, respectively, and TP1, TP2, and TP3 are spatially separated. Then, the SP1, SP2, SP3 and TP1, TP2, TP3 are all focused in the X-axis direction by the first cylindrical lens 11, and enter the nonlinear optical crystal 12 as focused light. The nonlinear optical crystal 12 is a material whose physical characteristics change only when two ultrashort light pulses are simultaneously incident on the crystal, and can respond at the speed of light, and thus operates as an ultrafast optical-optical switch. .

  Therefore, in the nonlinear optical crystal 12, only the ultrashort optical pulse signal component synchronized with the trigger pulses TP1, TP2, and TP3 is cut out from the nonlinear optical crystal 12.

In the present invention, SP1 is extracted by TP1, SP2 is extracted by TP2, and SP3 is extracted by TP3. At this time, since TP1, TP2, and TP3 are spatially separated, the cut SP1, SP2, and SP3 are also spatially separated and emitted from the nonlinear optical crystal 12. Thereafter, by collimating with the second cylindrical lens 13, the time-series signal component of the ultrashort light pulse is replaced with a spatial distribution along the X-axis direction and developed. In addition, since each extracted signal component retains a relative time difference between TP1, TP2, and TP3, the spatial distribution developed along the X-axis direction also actually corresponds to each time. It becomes a spatio-temporal profile that retains the time difference. Thereafter, the wavelength component is decomposed for each wavelength along the Y-axis direction using the dispersive element 14, and collimated again by the third cylindrical lens 15, whereby the time waveform of each wavelength component included in the ultrashort optical pulse is in the horizontal direction. An optical spectrogram of an ultrashort optical pulse signal can be obtained by arranging in the vertical direction (Y-axis direction) as a spatial distribution along the (X-axis direction) and for each included wavelength component.

  Now, it is assumed that TP1 and SP1, TP2 and SP2, and TP3 and SP3 are temporally synchronized. However, signal components that are synchronized with TP1, TP2, and TP3, respectively, for an unknown ultrashort optical pulse signal. Are cut out spatially separated.

  In the description, the trigger pulse is a discrete triple pulse as shown in FIG. 4A. However, by using a continuous pulse train as shown in FIG. Can be converted into a spatial distribution.

Further, as shown in FIG. 2, any wavelength component in the ultrashort optical pulse signal 102 is automatically mapped to a position corresponding to the time delay of the wavelength component. It becomes possible to automatically convert the pulse signal 102 into a two-dimensional spatial distribution.
[Second subsystem]
The second subsystem 111 performs dispersion compensation for the ultrashort optical pulse by performing time compensation on the developed optical spectrogram 112.

In the first subsystem 101, since the time delay amount and the spatial dispersion amount of the trigger pulse can be set in advance, the wavelength component existing at an arbitrary point on the developed spatial distribution and its time difference are known. Become. For example, taking FIG. 2 as an example, the distribution developed at the position (x = x ₁ ) is a time signal component having a time delay of (t = τ ₁ ) in the ultrashort optical pulse signal. Is a distribution advanced by an amount corresponding to z ₁ = τ ₁ × c. That is, the signals developed at the position (x = x ₁ ) have the same time difference uniquely. Therefore, it is possible to perform time compensation by placing an element that compensates for the time difference (z ₁ = τ ₁ × c) at that position.

There are two main methods for compensating for the time difference.
(Time compensation method I)
When the time waveform of the ultrashort optical pulse signal is developed into a spatial distribution, as shown in FIG. 4A, when it is developed discretely, the phase as a passive optical element (phase compensation means) that compensates for the time difference. Compensation can be achieved only by placing the compensation plate 25 without using an active optical device. Reference numeral 21 denotes an ultrafast gate, 22 denotes a first lens, and 23 denotes a second lens .
(Time compensation method II)
Further, as shown in FIG. 4B, when continuously deployed, a diffractive cylindrical lens pair 30 as a passive optical element (phase compensation means) is used.

  FIG. 5 is a diagram showing the state of dispersion compensation shown in FIG.

Since the ultrashort light pulse has a very short pulse width, it can be considered to be a sheet shape spatially indicated by A. This ultrashort light pulse enters the diffractive cylindrical lens 31. Light incident on each point [P ₁ (1), P ₁ (2), P ₁ (3)... P ₁ (n)] on the lens 31 is deflected by the lens 31 and condensed toward the point B. The Thereafter, the light diverges again from the point B and is deflected by the diffractive cylindrical lens 32 symmetrically arranged with the diffractive cylindrical lens 31 so as to be parallel to the incident light to the diffractive cylindrical lens 31. At this time, each point on the lens 31 [P ₁ (1), P ₁ (2), P ₁ (3)... P ₁ (n)] passes through the point B and each point on the lens 32 [P ₂ ( 1), P ₂ (2), P ₂ (3)... P ₂ (n)]. Since the ultrashort light pulse has a sheet shape, the difference in distance causes the wavefront of the ultrashort light pulse to be inclined. Using this slope, time compensation is performed. Since the wavefront is inclined in the continuously developed distribution, it is possible to compensate for the inclination of the wavefront by using the diffractive cylindrical lens pair 31 and 32. This makes it possible to perform time compensation.

Also, the dispersion compensation amount can be made variable by moving the above-described passive optical elements (here, the diffractive cylindrical lenses 31 and 32) electrically, magnetically, and mechanically.
[Third subsystem]
The third subsystem 121 converts the dispersion compensated distribution into an ultrashort optical pulse signal that can be transmitted again.

  The re-conversion to the ultrashort light pulse can be performed only by collecting the time-compensated distribution by the second subsystem 111 and making it incident on the optical fiber 125 by the optical system 124.

  As described above, according to the present invention, three steps are performed as follows in order to perform dispersion compensation for an ultrashort optical pulse signal whose amount of dispersion is unknown.

  In the first step, an ultrashort optical pulse signal as a transmission signal is developed into a time-wavelength two-dimensional spatial light spectrogram. That is, it develops on a plane having time as the X axis and wavelength as the Y axis. The amount of deviation from the center of the X axis is the amount of time deviation, and is automatically mapped to a spatial position corresponding to the amount of time deviation.

  In the second step, a passive optical element that performs time compensation on the developed optical spectrogram is arranged. Time compensation is performed by passing a thick passive optical element (for example, glass) with respect to the misalignment reference point (the signal that is delayed most).

  Compensation of the time shift amount from the reference time in the second step is realized by a diffractive cylindrical lens or a phase plate.

  The third step converts the time-compensated light distribution into an optical signal.

  As a result, real-time dispersion compensation that does not use any mechanical or active operation and makes the processing completely passive is possible. In particular, it is effective for high-speed and large-capacity transmission using ultrashort light pulses.

  In addition, this invention is not limited to the said Example, A various deformation | transformation is possible based on the meaning of this invention, and these are not excluded from the scope of the present invention.

  The dispersion compensation of the ultrashort optical pulse signal according to the present invention facilitates the introduction of the ultrashort optical pulse into the optical network system, and can greatly increase the communication capacity of the optical network system. As a result, the network environment surrounding daily life becomes more broadband, and multimedia communication such as videophones, which is difficult with current technology, can be realized.

It is a schematic diagram which shows the outline | summary of the dispersion compensation of the ultrashort optical pulse signal concerning this invention. It is a conceptual diagram which obtains the optical spectrogram of the ultrashort optical pulse signal concerning this invention. It is a schematic diagram of the optical system which implement | achieves the signal conversion concerning this invention. It is a schematic diagram which shows a mode that all the time components of the pulse train concerning this invention are converted into a spatial distribution. It is a schematic diagram which shows the mode of dispersion compensation of the ultrashort optical pulse signal concerning this invention.

Explanation of symbols

1 1 First Cylindrical Lens 12 Nonlinear Optical Crystal
13 Second cylindrical lens 14 Dispersing element
15 Third cylindrical lens 21 Super high-speed gate 22 First lens
23 second lens 25 phase compensation plate 30 diffractive cylindrical lens pair 31, 32 diffractive cylindrical lens 101 first subsystem 102, 102 ′ ultrashort optical pulse signal 104, 125 optical fiber transmission path 105, 124 optical system 111 first Two subsystems 112 Expanded two-dimensional spatial light spectrogram 113 Passive optical element 114 Distribution spectrogram with time compensation 121 Third subsystem 123, 123 ′ Converted ultrashort optical pulse signal

Claims (13)

An ultrashort optical pulse signal is developed using only light in a two-dimensional spatial light spectrogram representing temporal changes of each wavelength included in the ultrashort optical pulse signal, and the two-dimensional spatial optical spectrogram is converted into a two-dimensional modulation device. A dispersion compensation method for an ultrashort optical pulse signal that is directly modulated and converted again into an optical pulse signal, and a trigger pulse that is spatially separated from the signal light is operated as an optical-optical switch by a first cylindrical lens. The light is incident on a nonlinear optical crystal, and the signal light is spatially separated in the X-axis direction and cut out. The cut signal light is collimated by a second cylindrical lens, and then dispersed in the Y-axis direction for each wavelength. Dispersion compensation of ultra-short optical pulse signals, characterized in that the optical pulse signals decomposed and dispersed are compensated completely and instantaneously without using an active optical device. Law.   2. The dispersion compensation method for an ultrashort optical pulse signal according to claim 1, wherein the ultrashort optical pulse signal is an ultrashort optical pulse signal whose amount of dispersion is unknown.   2. The dispersion compensation method for an ultrashort optical pulse signal according to claim 1, wherein the ultrashort optical pulse signal is an ultrashort optical pulse signal having a multiplexed wavelength.   2. The dispersion compensation method for an ultrashort optical pulse signal according to claim 1, wherein a wavelength component having an arbitrary time delay in the dispersed ultrashort optical pulse signal is automatically developed at a predetermined spatial position. Dispersion compensation method for ultrashort optical pulse signal.   2. The dispersion compensation method for an ultrashort optical pulse signal according to claim 1, wherein the trigger pulse is a discrete triple pulse.   2. The dispersion compensation method for an ultrashort optical pulse signal according to claim 1, wherein the trigger pulse is a continuous pulse train. A dispersion compensation method for ultrashort optical pulse signals, wherein the spatial distribution developed in claim 4 can be compensated for dispersion by a passive optical element. 8. The dispersion compensation method for ultrashort optical pulse signals according to claim 7 , wherein a diffractive cylindrical lens pair is used as the passive optical element . 9. The dispersion compensation method for an ultrashort optical pulse signal according to claim 8 , wherein the dispersion compensation amount is made variable by moving the diffractive cylindrical lens pair electrically, magnetically, and mechanically. A dispersion compensation method for ultrashort optical pulse signals. An ultrashort optical pulse signal is developed using only light in a two-dimensional spatial spectrogram representing temporal changes of each wavelength included in the ultrashort optical pulse signal, and the two-dimensional spatial spectrogram is directly applied to the two-dimensional modulation device. A dispersion compensation device for an ultrashort optical pulse signal that is modulated and converted again into an ultrashort optical pulse signal, and the trigger pulse spatially separated from the signal light is operated as an optical-optical switch by a first cylindrical lens. Means for making it incident on the nonlinear optical crystal, and cutting out the signal light and the trigger pulse by separating the signal light in the X-axis direction and collimating the extracted signal light with a second cylindrical lens; Means to resolve each wavelength in the Y-axis direction using a dispersive element, and completely compensate for the dispersed ultrashort optical pulse signal without using an active optical device Dispersion compensation device of the ultrashort optical pulse signal, characterized by comprising means that. 11. The dispersion compensator for an ultrashort optical pulse signal according to claim 10 , further comprising means for instantaneously compensating an ultrashort optical pulse signal with an unknown dispersion amount without using an active optical device. Optical pulse signal dispersion compensator. 12. The dispersion compensator for an ultrashort optical pulse signal according to claim 10 , further comprising means for compensating passively the dispersion of the wavelength-multiplexed ultrashort optical pulse signal. Compensation device. 11. The dispersion compensator for an ultrashort optical pulse signal according to claim 10 , further comprising means for automatically expanding a wavelength component having an arbitrary time delay in the dispersed ultrashort optical pulse signal to a predetermined spatial position. An ultrashort optical pulse signal dispersion compensator.

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