WO2005083854A1 - コヒーレント光源およびその制御方法、並びにそれらを用いたディスプレイ装置およびレーザディスプレイ - Google Patents
コヒーレント光源およびその制御方法、並びにそれらを用いたディスプレイ装置およびレーザディスプレイ Download PDFInfo
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- WO2005083854A1 WO2005083854A1 PCT/JP2005/001009 JP2005001009W WO2005083854A1 WO 2005083854 A1 WO2005083854 A1 WO 2005083854A1 JP 2005001009 W JP2005001009 W JP 2005001009W WO 2005083854 A1 WO2005083854 A1 WO 2005083854A1
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- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01S—DEVICES USING THE PROCESS OF LIGHT AMPLIFICATION BY STIMULATED EMISSION OF RADIATION [LASER] TO AMPLIFY OR GENERATE LIGHT; DEVICES USING STIMULATED EMISSION OF ELECTROMAGNETIC RADIATION IN WAVE RANGES OTHER THAN OPTICAL
- H01S5/00—Semiconductor lasers
- H01S5/06—Arrangements for controlling the laser output parameters, e.g. by operating on the active medium
- H01S5/068—Stabilisation of laser output parameters
- H01S5/0683—Stabilisation of laser output parameters by monitoring the optical output parameters
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01S—DEVICES USING THE PROCESS OF LIGHT AMPLIFICATION BY STIMULATED EMISSION OF RADIATION [LASER] TO AMPLIFY OR GENERATE LIGHT; DEVICES USING STIMULATED EMISSION OF ELECTROMAGNETIC RADIATION IN WAVE RANGES OTHER THAN OPTICAL
- H01S5/00—Semiconductor lasers
- H01S5/06—Arrangements for controlling the laser output parameters, e.g. by operating on the active medium
- H01S5/062—Arrangements for controlling the laser output parameters, e.g. by operating on the active medium by varying the potential of the electrodes
- H01S5/0625—Arrangements for controlling the laser output parameters, e.g. by operating on the active medium by varying the potential of the electrodes in multi-section lasers
- H01S5/06255—Controlling the frequency of the radiation
- H01S5/06256—Controlling the frequency of the radiation with DBR-structure
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
- H04N9/00—Details of colour television systems
- H04N9/12—Picture reproducers
- H04N9/31—Projection devices for colour picture display, e.g. using electronic spatial light modulators [ESLM]
- H04N9/3129—Projection devices for colour picture display, e.g. using electronic spatial light modulators [ESLM] scanning a light beam on the display screen
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- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01S—DEVICES USING THE PROCESS OF LIGHT AMPLIFICATION BY STIMULATED EMISSION OF RADIATION [LASER] TO AMPLIFY OR GENERATE LIGHT; DEVICES USING STIMULATED EMISSION OF ELECTROMAGNETIC RADIATION IN WAVE RANGES OTHER THAN OPTICAL
- H01S5/00—Semiconductor lasers
- H01S5/005—Optical components external to the laser cavity, specially adapted therefor, e.g. for homogenisation or merging of the beams or for manipulating laser pulses, e.g. pulse shaping
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01S—DEVICES USING THE PROCESS OF LIGHT AMPLIFICATION BY STIMULATED EMISSION OF RADIATION [LASER] TO AMPLIFY OR GENERATE LIGHT; DEVICES USING STIMULATED EMISSION OF ELECTROMAGNETIC RADIATION IN WAVE RANGES OTHER THAN OPTICAL
- H01S5/00—Semiconductor lasers
- H01S5/005—Optical components external to the laser cavity, specially adapted therefor, e.g. for homogenisation or merging of the beams or for manipulating laser pulses, e.g. pulse shaping
- H01S5/0078—Optical components external to the laser cavity, specially adapted therefor, e.g. for homogenisation or merging of the beams or for manipulating laser pulses, e.g. pulse shaping for frequency filtering
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- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01S—DEVICES USING THE PROCESS OF LIGHT AMPLIFICATION BY STIMULATED EMISSION OF RADIATION [LASER] TO AMPLIFY OR GENERATE LIGHT; DEVICES USING STIMULATED EMISSION OF ELECTROMAGNETIC RADIATION IN WAVE RANGES OTHER THAN OPTICAL
- H01S5/00—Semiconductor lasers
- H01S5/005—Optical components external to the laser cavity, specially adapted therefor, e.g. for homogenisation or merging of the beams or for manipulating laser pulses, e.g. pulse shaping
- H01S5/0092—Optical components external to the laser cavity, specially adapted therefor, e.g. for homogenisation or merging of the beams or for manipulating laser pulses, e.g. pulse shaping for nonlinear frequency conversion, e.g. second harmonic generation [SHG] or sum- or difference-frequency generation outside the laser cavity
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- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01S—DEVICES USING THE PROCESS OF LIGHT AMPLIFICATION BY STIMULATED EMISSION OF RADIATION [LASER] TO AMPLIFY OR GENERATE LIGHT; DEVICES USING STIMULATED EMISSION OF ELECTROMAGNETIC RADIATION IN WAVE RANGES OTHER THAN OPTICAL
- H01S5/00—Semiconductor lasers
- H01S5/06—Arrangements for controlling the laser output parameters, e.g. by operating on the active medium
- H01S5/062—Arrangements for controlling the laser output parameters, e.g. by operating on the active medium by varying the potential of the electrodes
- H01S5/06226—Modulation at ultra-high frequencies
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01S—DEVICES USING THE PROCESS OF LIGHT AMPLIFICATION BY STIMULATED EMISSION OF RADIATION [LASER] TO AMPLIFY OR GENERATE LIGHT; DEVICES USING STIMULATED EMISSION OF ELECTROMAGNETIC RADIATION IN WAVE RANGES OTHER THAN OPTICAL
- H01S5/00—Semiconductor lasers
- H01S5/06—Arrangements for controlling the laser output parameters, e.g. by operating on the active medium
- H01S5/062—Arrangements for controlling the laser output parameters, e.g. by operating on the active medium by varying the potential of the electrodes
- H01S5/0625—Arrangements for controlling the laser output parameters, e.g. by operating on the active medium by varying the potential of the electrodes in multi-section lasers
- H01S5/06253—Pulse modulation
Definitions
- the present invention relates to a coherent light source using a wavelength conversion element and a control method thereof, and a display device and a laser display using the same.
- Fig. 11 shows a schematic configuration of a laser display 100 as an example of this type of conventional display device.
- coherent light from RGB three-color laser light sources 101a to 101c is intensity-modulated by optical modulators 106a to 106c according to an input video signal, and multiplexed by dichroic mirrors 102a and 102b.
- the polygon scanner (polygon mirror) 104 is driven in the horizontal direction and the galvanomirror 105 in the vertical direction, and a two-dimensional image is displayed on the screen 108.
- the light from each of the RGB light sources is monochromatic light. Therefore, by using a laser light source having an appropriate wavelength, the color range that can be displayed is wider than that of the NTSC signal, and the color purity is higher. A vivid image can be displayed.
- FIG. 12 shows a device connectable to this conventional laser display.
- This conventional laser display uses a RGB terminal to input video signals, and is integrated with a personal computer 201 such as a notebook PC, a video game machine 202, an optical disk player 203 such as various DVDs, and a VTR.
- Any device that has an RGB signal output terminal, such as the STB 211 for digital broadcasting, the STB 212 for terrestrial digital broadcasting, and the STB 213 for BS HD TV broadcasting, can be connected.
- D4 input terminal, DVI-D input terminal, IEEE1394 terminal, component terminal, S terminal according to the format of the signal output from the device connected to the laser display , A video terminal or the like may be provided.
- the red (R) light source needs to use a semiconductor laser
- the green (G) and blue (B) light sources need to use an SHG light source.
- the color range that can be displayed is wider than that of NTSC signals.Green light with a wavelength of about 530 nm and blue light with a wavelength of about 450 nm are required to enable the display of vivid images with high color purity.
- Patent Document 1 JP-A-2003-98476 (FIG. 1 on page 4)
- the present invention has been made to solve the above-described problem relating to the modulation of the light output of the SHG light source, and realizes gradation while increasing the speed of the output modulation of the SHG light source. It is an object.
- a coherent light source includes a semiconductor laser having an active region and a distributed Bragg reflection region, and a nonlinear optical crystal.
- An optical wavelength conversion element for converting the wavelength of the laser light emitted from the body laser, a photodetector for measuring a harmonic output from the optical wavelength conversion element, and an electric current separately flowing in the active region and the distributed Bragg reflection region.
- a current injection means for controlling the current injection means based on a harmonic output measured by the photodetector, so that an oscillation wavelength of the semiconductor laser is tilted in a phase matching wavelength spectrum of the optical wavelength conversion element.
- Pulsing the pulse current injection means to change the oscillation wavelength of the semiconductor laser to a desired value at the slope in the phase matching wavelength spectrum of the optical wavelength conversion element. Characterized in that it comprises a pulse current control means for.
- the harmonic output of the laser light emitted from the semiconductor laser and having its wavelength converted by the optical wavelength conversion element is measured by the photodetector.
- the current control means first controls the current injection means, adjusts the current applied to the active region and the distributed Bragg reflection region, and fixes the oscillation wavelength of the semiconductor laser to the slope in the phase matching wavelength spectrum.
- the pulse current injection means applies a pulse current to at least one of the active region and the distributed Bragg reflection region.
- the refractive index in the region to which the pulse current is applied is instantaneously reduced, and the wavelength of the harmonic shifts to the lower wavelength side, so that the harmonic output decreases.
- the harmonic output can be rapidly and continuously changed to a desired value.
- the method for controlling a coherent light source is a method for optically detecting a harmonic output from an optical wavelength conversion element which is made of a nonlinear optical crystal and converts the wavelength of laser light emitted from a semiconductor laser. And controlling a current applied to an active region and a distributed Bragg reflection region provided in the semiconductor laser based on an output of the photodetector.
- the harmonic output detected by the photodetector After fixing the harmonic output detected by the photodetector to the inclined portion in the phase matching wavelength panel of the optical wavelength conversion element, apply a pulse current to the active region or the distributed Bragg reflection region, The harmonic output detected by the photodetector is changed to a desired value at a slope in a phase matching wavelength spectrum of the optical wavelength conversion device. According to the coherent light source using the control method according to this aspect, it is possible to change the harmonic output to a desired value at high speed and continuously.
- FIG. 1 is a schematic configuration diagram of a laser display.
- FIG. 2 is a diagram showing an output adjustment device for an SHG light source
- FIG. 5 is a diagram showing a phase matching wavelength spectrum of an optical wavelength conversion element.
- FIG. 7 is a diagram showing harmonic output characteristics when a pulse current is applied to the DBR region
- FIG. 8 A flow chart showing a flow of processing when a pulse current is controlled in a DBR region and a harmonic output is controlled.
- FIG. 9 is a block diagram showing a schematic configuration of an SHG light source output adjusting device using a three-electrode LD according to Embodiment 2.
- FIG. 11 is a diagram showing a schematic configuration of a laser display
- FIG. 12 is a diagram showing devices that can be connected to a conventional laser display
- FIG. 1 shows a schematic configuration of a laser display.
- coherent light from laser light sources la to lc of three RGB colors is intensity-modulated in accordance with an input video signal, and multiplexed by dich-mouth mirrors (combining means) 2a and 2b. Further, they are horizontally scanned by a polygon scanner (polygon mirror, first scanning means) 4 composed of a rotating polygon mirror, and vertically scanned by a galvano mirror (second scanning means) 5. A two-dimensional image is displayed.
- the horizontal scanning means and the vertical scanning means are not limited to the above, and any combination of the polygon scanner 4 and the galvanometer mirror 5 is possible.
- SHG light sources were used for the light source lb for Green and the light source lc for Blue.
- For Red A semiconductor laser is used as the light source la, and output modulation can be performed directly at high speed.
- a display device a device having a configuration in which a screen is removed from a laser display is referred to as a display device.
- the SHG light source according to the first embodiment includes a semiconductor laser (DBR-LD) having an active region for providing a gain and a distributed Bragg reflection region (DBR region) for controlling an oscillation wavelength, and a nonlinear laser.
- DBR-LD semiconductor laser
- a light wavelength conversion element made of an optical crystal.
- the DBR-LD can change the oscillation wavelength of the semiconductor laser by applying a current to the DBR region, increasing the temperature of the DBR region, and changing the refractive index of the DBR region.
- FIG. 2 is a diagram showing a schematic configuration of an SHG light source and an output adjusting device of the SHG light source according to the first embodiment.
- the SHG light source alone, and the whole of the SHG light source and the output adjustment device of the SHG light source are referred to as a coherent light source.
- This output adjustment device is used to convert a semiconductor laser (DBR-LD) 51 having an active region 52 and a DBR region 53, an optical wavelength conversion element 56, and a harmonic emitted from the optical wavelength conversion element 56 into parallel light.
- DBR-LD semiconductor laser
- the active region 52 and the DBR region 53 are shown separately for explanation, but are actually integrated.
- the DBR-LD 51 and the optical wavelength conversion element 56 are integrated into an SHG light source 55.
- the control circuit 60 includes a microcomputer (current control means and pulse current control means) 61 for performing control, and a current (hereinafter, referred to as Iop) applied to an active region 52 of the semiconductor laser.
- Drive circuit (current injection means) 63 for controlling the current and a DBR drive circuit (current injection means) 64 for controlling the current (hereinafter referred to as Idbr) applied to the DBR region 53 are incorporated.
- an active area panel circuit (pulse current injection means) 65 for applying a pulse current to the active area 52 and a DBR area pulse circuit (pulse current injection means) 66 for applying a pulse current to the DBR area are added.
- the DBR-LD 51 is, for example, an AlGaAs semiconductor laser.
- the output was rated at 100 mW, the threshold was 30 mA, and the operating current at 100 mW output was 150 mA.
- the optical wavelength conversion element 56 a polarization inversion type optical waveguide device having an element length of 10 mm was used, and an optical waveguide and a periodic polarization inversion region were provided on a magnesium-doped lithium niobate substrate. Was.
- blue light is emitted from the light wavelength conversion element 56
- a DBR-LD51 that emits laser light in the 850 nm band
- the polarization inversion cycle may be set to 3.2 zm.
- blue light having a wavelength of about 425 nm can be obtained.
- green light is emitted from the wavelength conversion element 56, for example, a DBR-LD51 that emits laser light in the 1064 nm band may be used, and the polarization inversion cycle may be set to 6. Thereby, green light having a wavelength of about 532 nm can be obtained.
- a control method for obtaining a desired output in the SHG light source according to the first embodiment, modulating the output at a high speed, and realizing an output gradation will be described below.
- FIG. 3 shows a change in the oscillation wavelength of the DBR-LD with respect to a change in lop.
- ldbr 0 mA.
- the solid line in FIG. 3 shows the wavelength change when lop is increased.
- the dotted line in FIG. 3 shows the wavelength change when lop is reduced. From Fig. 3, it can be seen that the oscillation wavelength of the DBR-LD changes while repeating mode hops as the lop increases. This mode hop occurs because it is affected by the DBR region.
- the oscillation wavelength of the DBR-LD with respect to the change of lop has a hysteresis characteristic.
- the DBR-LD of the first embodiment it was confirmed that no mode hop was performed during a point (E point) force of ⁇ 30 mA immediately after the mode hop. This indicates that the mode hop point is the most stable point.
- the oscillation wavelength of a DBR-LD it is stable to change the wavelength near the mode hop point.
- the wavelength change at this time was 0.004 nmZmA. This means that the oscillation wavelength of the DBR-LD can be continuously changed by ⁇ 0.12 nm without mode hop.
- FIG. 5 shows a phase matching wavelength spectrum of the optical wavelength conversion element 56.
- the harmonic output is normalized by setting the peak output to “1”.
- the optical wavelength conversion element has a different conversion efficiency from the fundamental wave to the harmonic with respect to the oscillation wavelength of the semiconductor laser which is the fundamental wave.
- the optical wavelength conversion element length is: L 0 mm
- the allowable range of the phase matching wavelength (half width at half maximum) where the harmonic output is half of the peak output is very narrow at 0.08 nm.
- the phase-matched wavelength spectrum is a range of wavelengths including the peak wavelength and at which the harmonic output is minimized on the low wavelength side and the high wavelength side of the peak wavelength. That is, the side lobe in FIG. 5 is outside the phase matching wavelength spectrum.
- the peak wavelength refers to the wavelength at which the harmonic output is maximum (peak output).
- the oscillation wavelength of the semiconductor laser is fixed within the phase matching wavelength spectrum of the optical wavelength conversion element 56, and a harmonic output is obtained.
- the output of the harmonics can be changed, and the output gradation is possible. It becomes.
- the oscillation wavelength of the DBR-LD is limited only within a limited range ( ⁇ 0.12 nm in the present embodiment). It cannot be changed continuously. Therefore, in order to perform gradation in a wide range, it is necessary that the value of the wavelength to be changed is approximately larger than the half width at half maximum (0.008 nm in the present embodiment) of the phase matching wavelength spectrum. It is.
- the harmonic output is the peak output 5. / 0 or more,
- the portion that is 95% or less is defined as the slope (the thick line in the spectrum). This inclined portion has a characteristic that gradation is easy to perform because the output with respect to the wavelength changes almost linearly. Therefore, it is better to use a ramp to set the output of the SHG light source.
- one inclined portion is provided on each of a lower wavelength side and a higher wavelength side than the peak wavelength.
- the change in the oscillation wavelength of the DBR-LD due to lop and Idbr described above is a phenomenon that occurs thermally. This phenomenon occurs because the heat in the active region and the DBR region changes due to changes in lop and Idbr, and the refractive index in the active region and the DBR region fluctuates accordingly. Therefore, the change in the oscillation wavelength is a phenomenon that occurs on the order of msec, and is not sufficient as a speed for outputting a moving image as an image. To output a moving image, a wavelength change speed of at least the order of MHz, that is, the order of nsec power ⁇ sec is required.
- the pulse current was measured using a DBR region pulse circuit 66 for applying a pulse current to the DBR region.
- a pulse current is applied to the active region or the DBR region, for example, the carrier density inside the semiconductor increases, a phenomenon called a plasma effect occurs, and the refractive index of the DBR portion decreases instantaneously.
- the oscillation wavelength of the DBR-LD instantaneously shifts to the lower wavelength side, so that the output of harmonics decreases. Also, there is almost no thermal change due to the noise current.
- By controlling the oscillation wavelength of the DBR-LD at high speed by such wavelength control using the plasma effect it becomes possible to modulate the harmonic output in the order of nsec and to perform gradation.
- the oscillation wavelength of the DBR-LD was controlled and fixed at point A in the phase matching wavelength spectrum of FIG.
- a pulse current as shown in Fig. 6 was applied to the DBR region to generate a plasma effect.
- a rectangular pulse is applied to the DBR region as an example of the pulse current.
- one of the major factors affecting the plasma effect is the shape of the rising part of the pulse. As the inclination of the rising portion is steeper, the carrier density instantaneously increases, so that the plasma effect can be effectively generated. Therefore, it is preferable to use a rectangular pulse as compared with, for example, a triangular pulse or a pulse having a blunt rising portion.
- the width of the pulse may be arbitrarily set because it hardly affects the plasma effect. However, if the pulse width is wide, heat is generated in the DBR region. Therefore, the pulse width is preferably as narrow as possible.
- FIG. 7 is a diagram showing a change in harmonic output (dot-dash line in the figure) when a pulse current (solid line in the figure) similar to that in FIG. 6 is applied after fixing to point A.
- the control is performed such that the harmonic output decreases linearly at an arbitrary time up to the target output value A7 at time t7. That is, it is assumed that the output values A1 to A7 of the harmonics are the target output values at times t1 to t7, respectively.
- FIG. 8 is a flowchart showing the flow of processing when the pulse current is supplied to the DBR region and the harmonic output is controlled.
- the microcomputer 61 calculates a target output value A1 at the time tl so that the target output value A7 is obtained at the time t7 (step S101). Subsequently, the microcomputer 61 calculates the height of the pulse current that achieves the target output value A1 (step S102), and controls the pulse circuit 66 for the DBR region to calculate the calculated height.
- the applied pulse current is applied to the DBR section (step S103). As a result, the oscillation wavelength of the DBR-LD shifts to the lower wavelength side (step S104).
- the pulse current should have a linear value as shown by the dotted line in Fig. 8. However, in reality, there is a temperature change in the DBR region, etc., so that even if the pulse current of the required height is adjusted, the harmonic output does not reach the target output value, in many cases.
- step S105 the harmonic output emitted from the light wavelength conversion element 56 is measured by the photodetector 59 (step S105). Since the time t7 has not yet been reached, the control has not been completed (No in step S106), and the process returns to step S101 to perform feedback control based on the value measured by the photodetector 59. For example, assuming that the output of the pulse current at time tl is higher than the target output value A1, the height of the pulse current at time t2 calculated in step S102 is the ideal value indicated by the dotted line. Need to be larger than Hereinafter, the above processing is sequentially performed, and if the harmonic output measured at the previous time is larger than the target output value, it is necessary to further reduce the output value.
- a predetermined coefficient is set according to the difference between the target output value and the value measured by the photo detector 59. It may be configured to hang.
- the harmonic output changes instantaneously as the output changes (in this case, the output decreases) according to the amplitude (pulse height) of the pulse current.
- continuous gradation can be achieved by using the slope of the phase matching wavelength spectrum.
- the first embodiment it is possible to set the output of the harmonic whose wavelength has been converted by the optical wavelength converter using the DBR-LD to a desired value at a high speed. .
- high-speed modulation and gradation of the laser light source can be performed, and the device can be used for a device such as a display device that requires high-speed response and output control.
- the microcomputer 61 stops the supply of lop to the active area when the scan reaches the edge of the screen, and during that time checks and re-adjusts the DBR current to prepare for a stable harmonic output.
- a high-output signal may be continuously output.
- the temperature of the DBR-LD may gradually increase. pulse
- the microcomputer 61 can be configured so as to gradually change lop and Idbr little by little to cancel a wavelength change caused by an increase in heat.
- a semiconductor laser (3) including an active region for providing a gain, a distributed Bragg reflection region (DBR region) for controlling an oscillation wavelength, and a phase region for continuously changing a wavelength (3).
- DBR region distributed Bragg reflection region
- a method for controlling an SHG light source including an electrode LD) and a light wavelength conversion element made of a nonlinear optical crystal will be described.
- the three-electrode LD applies a current to the phase region to change the refractive index of the phase region, thereby changing the substantial resonator length of the semiconductor laser to continuously oscillate the oscillation wavelength of the semiconductor laser without mode hopping. It is possible to change it.
- FIG. 9 is a diagram showing a schematic configuration of an output adjusting device for an SHG light source according to the second embodiment.
- This output adjusting device is configured to convert a semiconductor laser (three-electrode LD) 74 having an active region 75, a DBR region 77, and a phase region 76, an optical wavelength conversion element 80, and a harmonic emitted from the optical wavelength conversion element 80 into parallel.
- the active region 75, the DBR region 77, and the phase region 76 are shown as being separated for explanatory purposes.
- the three-electrode LD 74 and the optical wavelength conversion element 80 are integrated into an SHG light source 78.
- the control circuit 84 includes a microcomputer (current control means and pulse current control means) 85 for performing control, and a current (lop) for controlling a current (lop) applied to the active region 75 of the semiconductor laser.
- the laser drive circuit 88, the DBR drive circuit 86, and the phase section drive circuit 87 have a function as a current injection unit in the present embodiment.
- an active region pulse circuit 95 for applying a pulse current to the active region 75, a DBR region pulse circuit 97 for applying a pulse current to the DBR region 77, and a phase region noise circuit for applying a pulse current to the phase region 76 96 is added.
- the active region noise circuit 95, the DBR region pulse circuit 97, and the phase region pulse circuit 96 have a function as pulse current injection means in the present embodiment.
- the three-electrode LD 74 has a continuously tunable characteristic as shown in FIG.
- Idbr and Iphase cannot be continuously tuned unless they are changed at a certain ratio
- This ratio is not limited to 1.6, but may be arbitrary.
- the optical wavelength conversion element 80 the same one as in the first embodiment was used.
- the oscillation wavelength of the semiconductor laser can be continuously varied, so that the oscillation wavelength is fixed within the phase matching wavelength spectrum of the optical wavelength conversion element. It will be very easy to do.
- the slope portion of the phase matching wavelength spectrum of the optical wavelength conversion element it is possible to easily change the harmonic output and obtain a desired harmonic output.
- the inclined portion referred to here is a portion where the harmonic output is 5% or more of the peak output and 95% or less of the peak output in the phase matching wavelength spectrum shown in Fig. 5 as in the first embodiment. Is preferred. In order to set the output of the SHG light source, it is better to use a slope.
- the slope portion where the harmonic output is 5% or more and 95% or less of the peak output has a characteristic that the output with respect to the wavelength changes almost linearly, so that gradation is easy.
- the error accuracy of the control circuit is about ⁇ 5%, when using parts other than the sloped part, for example, when the harmonic output is fixed to a point exceeding 95% of the peak output, the three-electrode LD This is because there is a risk that a desired value cannot be obtained even if the oscillation wavelength is changed.
- the change in the oscillation wavelength of the three-electrode LD due to lop, Idbr, and Iphase described above is a phenomenon that occurs thermally. This phenomenon occurs because the heat in the active region, DBR region, and phase region changes due to changes in lop, Idbr, and Iphase, and the refractive index in the active region, DBR region, and phase region fluctuates accordingly. Therefore, the change in oscillation wavelength is a phenomenon that occurs on the order of msec, and is not sufficient as a speed for outputting moving images as video.
- Video In order to output light, a wavelength change speed of at least the order of MHz, that is, from nsec to several / isec is required.
- a pulse circuit 95 for an active region that applies a pulse current to the active region a pulse circuit 97 for a DBR region that applies a pulse current to the DBR region, and a phase region that applies a pulse current to the phase region
- a pulse current was applied using the pulse circuit 96 for application.
- a pulse current is applied to the active region, DBR region, or phase region, for example, the carrier density inside the semiconductor increases, a phenomenon called a plasma effect occurs, and the refractive index of each part decreases instantaneously.
- the oscillation wavelength of the three-electrode LD shifts instantaneously to the lower wavelength side. Also, since it is a pulse current, there is almost no thermal change.
- the oscillation wavelength of the three-electrode LD was controlled, and fixed to point A in FIG. 5, as in the first embodiment.
- a plasma effect was generated by applying a noise current to the phase region and the DBR region. Due to this plasma effect, the refractive indices of the phase part and the DBR part were instantaneously reduced, and the output of the harmonics was instantaneously reduced because the oscillation wavelength of the three-electrode LD was shortened.
- the wavelength change can be realized by applying pulse current only to the DBR region or applying pulse current only to the phase region. As a result, even when a three-electrode LD was used, the characteristics shown in FIG. 7 were obtained, and continuous gradation was possible.
- the second embodiment it is possible to set the output of the harmonic whose wavelength has been converted by the optical wavelength conversion element using the three-electrode LD to a desired value at a high speed. .
- high-speed modulation and gradation of the laser light source can be performed, and the device can be used for a device requiring a high-speed response, such as a display device.
- the microcomputer 85 stops the supply of the lop to the active area when the scan reaches the edge of the screen, during which time the Idbr and Iphase are checked and readjusted to prepare for a stable output of the harmonic output.
- a high-output signal may be continuously output.
- the temperature of the three-electrode LD may gradually increase.
- the microcomputer 85 can be configured so as to gradually change Iphase and Idbr in advance so as to cancel a wavelength change caused by an increase in heat.
- LiNbO LiNbO
- LiTa ⁇ LiTa ⁇
- KTP KTiOPoO
- optical wavelength conversion elements 56, 8 are RbTiOAsO, RbTiOPO, etc. can also be used. Furthermore, the optical wavelength conversion elements 56, 8
- a nonlinear organic polymer or the like may be used as a material of 0, a nonlinear organic polymer or the like may be used.
- the coherent light source according to the present invention comprises a semiconductor laser having an active region and a distributed Bragg reflection region, and a non-linear optical crystal, and a laser emitted from the semiconductor laser.
- a light wavelength conversion element for converting the wavelength of light a light detector for measuring a harmonic output from the light wavelength conversion element, and a current injection means for individually applying a current to the active region and the distributed Bragg reflection region.
- a pulse current injection means for applying a pulse current to the region, and controlling the pulse current injection means based on a harmonic output measured by the photodetector, and changing an oscillation wavelength of the semiconductor laser to the optical wavelength conversion element.
- Pulse current control means for changing to a desired value at an inclined portion in the phase matching wavelength spectrum.
- the harmonic output of the laser light emitted from the semiconductor laser and having its wavelength converted by the light wavelength conversion element is measured by the photodetector.
- the current control means first controls the current injection means, adjusts the current applied to the active region and the distributed Bragg reflection region, and fixes the oscillation wavelength of the semiconductor laser to the slope in the phase matching wavelength spectrum. .
- the pulse current injection means applies the pulse current to at least four regions of the active region and the distributed Bragg reflection region.
- the refractive index in the region to which the pulse current is applied is instantaneously reduced, and the wavelength of the harmonic shifts to the lower wavelength side, so that the harmonic output decreases.
- the harmonic output can be rapidly and continuously changed to a desired value.
- the coherent light source is the coherent light source (1), wherein the current control means controls the current injection means to apply a current to the active region when stopping harmonic output. Stopping is a special feature.
- the harmonic output becomes zero. Therefore, by stopping the current applied to the active region, the harmonic output can be reliably stopped.
- the coherent light source is the coherent light source (1), wherein the pulse current control means controls the pulse current injection means when stopping the output of the harmonic wave, thereby controlling the active region and the distributed Bragg. It is characterized in that a pulse current is applied to the reflection area.
- the coherent light source is a coherent light source (3), and the pulse current applied by the pulse current injecting means has a higher harmonic wavelength due to the pulse current, and a phase matching wavelength spectrum of the optical wavelength conversion element. It has a pulse height that fluctuates outward.
- the coherent light source is the coherent light source (1) or (2), wherein the current applied to the distributed Bragg reflection region is adjusted when the harmonic output is stopped. I do.
- the coherent light source is any of the coherent light sources (1) to (5), and when the high-power state of the harmonics is continuous, the current control means controls the current injection means, A current applied to at least one of the active region and the distributed Bragg reflection region is adjusted to keep the wavelength of the harmonic wave constant.
- the coherent light source is a coherent light source (1), wherein the semiconductor laser is further provided with a phase region, and the current injection means applies a current also to the phase region.
- the current control means controls the current injection means based on a harmonic output measured by the photodetector, and changes a current applied to the distributed Bragg reflection region and the phase region at a constant ratio.
- the oscillation wavelength of the semiconductor laser The wavelength conversion element is fixed to an inclined portion in a phase matching wavelength spectrum of the wavelength conversion element, and the panelless current injection unit is configured to apply a pulse to at least one of the active region, the distributed Bragg reflection region, and the phase region. It is characterized by the ability to reduce the current.
- the harmonic output of the laser light emitted from the semiconductor laser and having its wavelength converted by the light wavelength conversion element is measured by the photodetector.
- the current control means controls the current injection means, adjusts the current applied to the active region, the distributed Bragg reflection region and the phase region, and adjusts the oscillation wavelength of the semiconductor laser within the phase matching wavelength spectrum.
- the pulse current injection means applies the pulse current to at least one of the active region, the distributed Bragg reflection region, and the phase region.
- the refractive index in the region to which the pulse current is applied instantaneously decreases, and the wavelength of the harmonic shifts to the lower wavelength side, so that the harmonic output decreases.
- the degree to which the harmonic output is reduced is controlled by the pulse current control means, the harmonic output can be rapidly and continuously changed to a desired value.
- the coherent light source is a coherent light source (7), wherein the current control means controls the current injection means to apply a current to the active region when stopping harmonic output. Stopping is a special feature.
- the harmonic output becomes zero. Therefore, by stopping the current applied to the active region, the harmonic output can be reliably stopped.
- the coherent light source is a coherent light source (7), wherein the pulse current control means controls the pulse current injection means when stopping the output of the harmonic wave, so that the active region and the distributed Bragg are controlled.
- a pulse current is applied to a plurality of regions out of the reflection region and the phase region.
- the wavelength of the harmonic can be instantaneously changed to outside the phase matching wavelength spectrum, and the output of the harmonic can be stopped.
- the coherent light source is a coherent light source (9), wherein the pulse current applied by the pulse current injecting means is such that the wavelength of a higher harmonic wave by the pulse current is a phase matching wavelength spectrum of the optical wavelength conversion element. It has a pulse height that fluctuates outward.
- the coherent light source is the coherent light source (7) or (8), and adjusts a current applied to the distributed Bragg reflection region or the phase region when the output of the harmonic is stopped. It is characterized by.
- the coherent light source is any of the coherent light sources (7) to (11), and when the high-power state of the harmonics is continuous, the current control means controls the current injection means, A current applied to at least one of the active region, the distributed Bragg reflection region, and the phase region is adjusted to keep the wavelength of the harmonic wave constant.
- the coherent light source is any one of the coherent light sources (1) to (12), and the inclined portion in the phase matching wavelength spectrum is high in the phase matching wavelength spectrum.
- the harmonic output is the part where the peak output is 5% or more and 95% or less of the peak output.
- the portion where the harmonic output is 5% or more and 95% or less of the peak output changes almost linearly. Therefore, by fixing the oscillation wavelength of the semiconductor laser to the inclined portion, the gradation can be changed continuously and easily.
- the coherent light source is a coherent light source (13), and the inclined portion in the phase matching wavelength spectrum is a portion on the wavelength side lower than a peak wavelength in the phase matching wavelength spectrum. It is characterized by.
- the current applied to the distributed Bragg reflection region can be made smaller than when the wavelength is fixed to the portion on the higher wavelength side, so that the power consumption is suppressed. be able to.
- the coherent light source is any of the coherent light sources (1) to (14), wherein the current control means controls a current injection means to apply a current applied to the distributed Bragg reflection region to the semiconductor.
- the laser oscillation wavelength is fixed immediately after the mode hop.
- the oscillation wavelength of the semiconductor laser is mode hopped, mode hops occur due to temperature change or the like, and the oscillation wavelength becomes unstable immediately. Therefore, the oscillation wavelength can be stabilized by fixing it immediately after the mode hop.
- the coherent light source is any of the coherent light sources (1) to (15), wherein the pulse current applied by the pulse current injection means is a rectangular pulse.
- the carrier density in the semiconductor to which the rectangular panel is added is increased, and the harmonic output is reduced instantaneously. be able to.
- the display device is a display device that projects laser light whose intensity is modulated according to an input video signal, and includes a laser light source that emits red laser light and In (1) to (16), which emit blue laser light, Combining the coherent light source described above, the coherent light source according to any one of (1) to (16), which emits green laser light, and the red, blue, and green laser lights into one laser light Multiplexing means, first scanning means for scanning one laser beam multiplexed by the multiplexing means in a predetermined first direction, and a laser beam scanned in the first direction. And second scanning means for scanning in the second direction perpendicular to the first direction.
- the coherent light source that changes the oscillation wavelength of the semiconductor laser instantaneously by applying a pulse current is used as the light source of the blue and green laser lights, the output modulation can be performed at high speed. It is possible to realize a display device which can perform the operation and can obtain a continuous gradation.
- the display device is a display device (17), wherein the first running means and the second running means are selected from a polygon mirror comprising a rotating polygon mirror and a galvanomirror. Characterized by a combination of
- a laser display according to the present invention includes the display device according to (17) or (18), and a screen that projects laser light from the display device.
- a laser display wherein, at an end of the screen, the current control means, which receives the input video signal, controls the current injection means to stop supplying current to the active region, and stops the current from the semiconductor laser. When the output is stopped, the current control means adjusts the current applied to the distributed Bragg reflection region.
- the current control means continuously adjusts the current applied to the distributed Bragg reflection area. This includes, for example, checking and re-adjusting the current flowing into the distributed Bragg reflection region. It is. Thereby, when the suspension of the output from the semiconductor laser is released, the laser beam can be stably output.
- the method for controlling a coherent light source provides a method of controlling a harmonic output from an optical wavelength conversion element that is made of a nonlinear optical crystal and converts the wavelength of laser light emitted from a semiconductor laser. Is detected by a photodetector, and based on the output of the photodetector, the current applied to the active region and the distributed Bragg reflection region provided in the semiconductor laser is controlled to control the harmonic detected by the photodetector. After fixing the wave output to an inclined portion in the phase matching wavelength spectrum of the optical wavelength conversion element, a pulse current is applied to the active region or the distributed Bragg reflection region, and the harmonic detected by the photodetector is applied. It is characterized in that the wave output is changed to a desired value at a slope in the phase matching wavelength spectrum of the light wavelength conversion element.
- the main applications of the coherent light source described above include a drawing device, a measuring device, an optical disk device, and the like in addition to the display device described above.
- a coherent light source using a wavelength conversion element which is useful in the present invention, can modulate an SHG light source at high speed, and is useful, for example, as a light source for a display.
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- Physics & Mathematics (AREA)
- Optics & Photonics (AREA)
- Condensed Matter Physics & Semiconductors (AREA)
- General Physics & Mathematics (AREA)
- Electromagnetism (AREA)
- Engineering & Computer Science (AREA)
- Multimedia (AREA)
- Signal Processing (AREA)
- Optical Modulation, Optical Deflection, Nonlinear Optics, Optical Demodulation, Optical Logic Elements (AREA)
- Control Of Indicators Other Than Cathode Ray Tubes (AREA)
- Lasers (AREA)
- Semiconductor Lasers (AREA)
Abstract
Description
Claims
Priority Applications (3)
Application Number | Priority Date | Filing Date | Title |
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US10/555,500 US7356056B2 (en) | 2004-02-27 | 2005-01-26 | Coherent light source and control method thereof, and display unit and laser display using them |
JP2006519328A JPWO2005083854A1 (ja) | 2004-02-27 | 2005-01-26 | コヒーレント光源およびその制御方法、並びにそれらを用いたディスプレイ装置およびレーザディスプレイ |
EP05709349A EP1720224A4 (en) | 2004-02-27 | 2005-01-26 | COHERENT LIGHT SOURCE AND METHOD FOR CONTROLLING THE SAME, AND DISPLAY UNIT AND LASER DISPLAY USING SAME |
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JP2004054096 | 2004-02-27 | ||
JP2004-054096 | 2004-02-27 |
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WO2005083854A1 true WO2005083854A1 (ja) | 2005-09-09 |
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PCT/JP2005/001009 WO2005083854A1 (ja) | 2004-02-27 | 2005-01-26 | コヒーレント光源およびその制御方法、並びにそれらを用いたディスプレイ装置およびレーザディスプレイ |
Country Status (5)
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US (1) | US7356056B2 (ja) |
EP (1) | EP1720224A4 (ja) |
JP (1) | JPWO2005083854A1 (ja) |
CN (1) | CN100424946C (ja) |
WO (1) | WO2005083854A1 (ja) |
Cited By (6)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP2007156438A (ja) * | 2005-11-11 | 2007-06-21 | Matsushita Electric Ind Co Ltd | 表示装置 |
JP2007183624A (ja) * | 2005-12-29 | 2007-07-19 | Samsung Electro Mech Co Ltd | 回折型光変調器を利用するラスタースキャニング方式のディスプレイ装置 |
EP1843437A1 (en) * | 2006-04-04 | 2007-10-10 | Samsung Electronics Co., Ltd. | DFB laser with monolithically integrated MMI and second harmonic generation |
JP2010507250A (ja) * | 2006-10-16 | 2010-03-04 | コーニング インコーポレイテッド | 半導体レーザの波長選択、位相及び利得領域における波長制御 |
JP2010507251A (ja) * | 2006-10-16 | 2010-03-04 | コーニング インコーポレイテッド | 半導体レーザの波長制御 |
JP7473850B2 (ja) | 2021-01-20 | 2024-04-24 | 日本電信電話株式会社 | 波長変換装置 |
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Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP5303124B2 (ja) * | 2007-07-19 | 2013-10-02 | 住友電工デバイス・イノベーション株式会社 | 半導体レーザ装置の制御方法 |
US8050302B2 (en) * | 2007-12-07 | 2011-11-01 | Panasonic Corporation | Wavelength conversion laser light source, laser light source device and two-dimensional image display device adopting the same, and method of setting temperature of wavelength conversion element |
US20100322272A1 (en) * | 2007-12-31 | 2010-12-23 | Martin Hai Hu | Minimizing power variations in laser sources |
WO2009093439A1 (ja) * | 2008-01-21 | 2009-07-30 | Panasonic Corporation | 波長変換レーザ、画像表示装置、及びレーザ加工装置 |
US20090252187A1 (en) * | 2008-04-07 | 2009-10-08 | Anthony Sebastian Bauco | Minimizing Power Variations In Laser Sources |
JP2013174812A (ja) * | 2012-02-27 | 2013-09-05 | Osaka Univ | レーザ装置 |
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WO2017106735A1 (en) * | 2015-12-18 | 2017-06-22 | Aquifi, Inc. | System and method for speckle reduction in laser projectors |
CN105388690A (zh) * | 2015-12-24 | 2016-03-09 | 中国科学院半导体研究所 | 一种激光器显示系统 |
Citations (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP2001267680A (ja) * | 2000-03-22 | 2001-09-28 | Matsushita Electric Ind Co Ltd | レーザ光発生装置および光学的記録特性評価装置 |
JP2002043698A (ja) | 1999-12-22 | 2002-02-08 | Yokogawa Electric Corp | Shgレーザ光源及びshgレーザ光源の変調方法 |
JP2003298177A (ja) * | 2002-03-29 | 2003-10-17 | Matsushita Electric Ind Co Ltd | 光源装置の制御方法 |
US20030210760A1 (en) | 2002-05-13 | 2003-11-13 | Nelson Alan C. | Method and apparatus for emission computed tomography using temporal signatures |
JP2004014647A (ja) * | 2002-06-04 | 2004-01-15 | Matsushita Electric Ind Co Ltd | 半導体レーザ |
Family Cites Families (13)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPH0632332B2 (ja) * | 1984-08-24 | 1994-04-27 | 日本電気株式会社 | 半導体レ−ザ装置 |
JPH06295159A (ja) | 1993-04-09 | 1994-10-21 | Matsushita Electric Ind Co Ltd | レーザディスプレイ装置 |
JP3026291B2 (ja) * | 1993-09-30 | 2000-03-27 | 安藤電気株式会社 | 位相連続周波数可変光源 |
JPH10506724A (ja) * | 1994-10-03 | 1998-06-30 | エスディーエル インク. | チューニング可能な青色レーザダイオード |
US5835650A (en) * | 1995-11-16 | 1998-11-10 | Matsushita Electric Industrial Co., Ltd. | Optical apparatus and method for producing the same |
US6130901A (en) * | 1997-05-07 | 2000-10-10 | Matsushita Electric Industrial Co., Ltd. | SHG laser stabilizing control device and optical disk recording/reproduction device |
US6195184B1 (en) * | 1999-06-19 | 2001-02-27 | The United States Of America As Represented By The Administrator Of The National Aeronautics And Space Administration | High-resolution large-field-of-view three-dimensional hologram display system and method thereof |
JP3329446B2 (ja) | 1999-10-25 | 2002-09-30 | 松下電器産業株式会社 | コヒーレント光源およびその制御方法 |
JP2002043683A (ja) | 2000-07-19 | 2002-02-08 | Yokogawa Electric Corp | Shgレーザ光源の制御パラメータ算出装置及びshgレーザ光源の制御パラメータ算出方法 |
CN1302587C (zh) * | 2001-06-22 | 2007-02-28 | 松下电器产业株式会社 | 光源装置 |
US6594090B2 (en) * | 2001-08-27 | 2003-07-15 | Eastman Kodak Company | Laser projection display system |
JP2003295243A (ja) * | 2002-04-04 | 2003-10-15 | Canon Inc | 高調波光源装置、その駆動方法、およびそれを用いた画像表示装置、画像形成装置、光記録装置 |
US7230657B2 (en) * | 2002-05-03 | 2007-06-12 | Hewlett-Packard Development Company, L.P. | Light emitting device projection methods and systems |
-
2005
- 2005-01-26 WO PCT/JP2005/001009 patent/WO2005083854A1/ja active Application Filing
- 2005-01-26 CN CNB2005800002218A patent/CN100424946C/zh not_active Expired - Fee Related
- 2005-01-26 JP JP2006519328A patent/JPWO2005083854A1/ja not_active Withdrawn
- 2005-01-26 US US10/555,500 patent/US7356056B2/en not_active Expired - Fee Related
- 2005-01-26 EP EP05709349A patent/EP1720224A4/en not_active Withdrawn
Patent Citations (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP2002043698A (ja) | 1999-12-22 | 2002-02-08 | Yokogawa Electric Corp | Shgレーザ光源及びshgレーザ光源の変調方法 |
JP2001267680A (ja) * | 2000-03-22 | 2001-09-28 | Matsushita Electric Ind Co Ltd | レーザ光発生装置および光学的記録特性評価装置 |
JP2003298177A (ja) * | 2002-03-29 | 2003-10-17 | Matsushita Electric Ind Co Ltd | 光源装置の制御方法 |
US20030210760A1 (en) | 2002-05-13 | 2003-11-13 | Nelson Alan C. | Method and apparatus for emission computed tomography using temporal signatures |
JP2004014647A (ja) * | 2002-06-04 | 2004-01-15 | Matsushita Electric Ind Co Ltd | 半導体レーザ |
Non-Patent Citations (3)
Title |
---|
OSINSKI ET AL.: "Electronically tunable, 1-W CW, near-diffraction-limited monolithic flared amplifier-master oscillator power amplifier (MFA-MOPA)", IEEE PHOTONICS TECHNOLOGY LETTERS, 1994, pages 885 - 887 |
See also references of EP1720224A4 * |
TOHMORI ET AL.: "Wavelength tuning of GALNASP/INP integrated laser with butt-joined built-in distributed Bragg reflector", ELECTRONICS LETTERS, 1983, pages 656 - 657 |
Cited By (6)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP2007156438A (ja) * | 2005-11-11 | 2007-06-21 | Matsushita Electric Ind Co Ltd | 表示装置 |
JP2007183624A (ja) * | 2005-12-29 | 2007-07-19 | Samsung Electro Mech Co Ltd | 回折型光変調器を利用するラスタースキャニング方式のディスプレイ装置 |
EP1843437A1 (en) * | 2006-04-04 | 2007-10-10 | Samsung Electronics Co., Ltd. | DFB laser with monolithically integrated MMI and second harmonic generation |
JP2010507250A (ja) * | 2006-10-16 | 2010-03-04 | コーニング インコーポレイテッド | 半導体レーザの波長選択、位相及び利得領域における波長制御 |
JP2010507251A (ja) * | 2006-10-16 | 2010-03-04 | コーニング インコーポレイテッド | 半導体レーザの波長制御 |
JP7473850B2 (ja) | 2021-01-20 | 2024-04-24 | 日本電信電話株式会社 | 波長変換装置 |
Also Published As
Publication number | Publication date |
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CN1771639A (zh) | 2006-05-10 |
EP1720224A4 (en) | 2008-08-27 |
CN100424946C (zh) | 2008-10-08 |
JPWO2005083854A1 (ja) | 2007-11-29 |
US7356056B2 (en) | 2008-04-08 |
EP1720224A1 (en) | 2006-11-08 |
US20060209913A1 (en) | 2006-09-21 |
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