CN1285931A - Optical system and method for changing the lengths of optical paths and the phases of light beams - Google Patents
Optical system and method for changing the lengths of optical paths and the phases of light beams Download PDFInfo
- Publication number
- CN1285931A CN1285931A CN 98813074 CN98813074A CN1285931A CN 1285931 A CN1285931 A CN 1285931A CN 98813074 CN98813074 CN 98813074 CN 98813074 A CN98813074 A CN 98813074A CN 1285931 A CN1285931 A CN 1285931A
- Authority
- CN
- China
- Prior art keywords
- phase converter
- change
- phase
- light path
- optical system
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
Images
Classifications
-
- G—PHYSICS
- G02—OPTICS
- G02F—OPTICAL DEVICES OR ARRANGEMENTS FOR THE CONTROL OF LIGHT BY MODIFICATION OF THE OPTICAL PROPERTIES OF THE MEDIA OF THE ELEMENTS INVOLVED THEREIN; NON-LINEAR OPTICS; FREQUENCY-CHANGING OF LIGHT; OPTICAL LOGIC ELEMENTS; OPTICAL ANALOGUE/DIGITAL CONVERTERS
- G02F1/00—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics
- G02F1/01—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour
- G02F1/0121—Operation of devices; Circuit arrangements, not otherwise provided for in this subclass
-
- G—PHYSICS
- G02—OPTICS
- G02F—OPTICAL DEVICES OR ARRANGEMENTS FOR THE CONTROL OF LIGHT BY MODIFICATION OF THE OPTICAL PROPERTIES OF THE MEDIA OF THE ELEMENTS INVOLVED THEREIN; NON-LINEAR OPTICS; FREQUENCY-CHANGING OF LIGHT; OPTICAL LOGIC ELEMENTS; OPTICAL ANALOGUE/DIGITAL CONVERTERS
- G02F1/00—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics
- G02F1/01—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour
- G02F1/21—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour by interference
- G02F1/225—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour by interference in an optical waveguide structure
- G02F1/2257—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour by interference in an optical waveguide structure the optical waveguides being made of semiconducting material
-
- G—PHYSICS
- G02—OPTICS
- G02F—OPTICAL DEVICES OR ARRANGEMENTS FOR THE CONTROL OF LIGHT BY MODIFICATION OF THE OPTICAL PROPERTIES OF THE MEDIA OF THE ELEMENTS INVOLVED THEREIN; NON-LINEAR OPTICS; FREQUENCY-CHANGING OF LIGHT; OPTICAL LOGIC ELEMENTS; OPTICAL ANALOGUE/DIGITAL CONVERTERS
- G02F2201/00—Constructional arrangements not provided for in groups G02F1/00 - G02F7/00
- G02F2201/12—Constructional arrangements not provided for in groups G02F1/00 - G02F7/00 electrode
- G02F2201/126—Constructional arrangements not provided for in groups G02F1/00 - G02F7/00 electrode push-pull
Abstract
The optical system comprises two optical paths (P1, P2), and an arrangement for changing the length of the two paths including two phase modulators (M1, M2) one coupled to each of the paths. A driving system (Figure 3) applies power to the phase modulators to drive them in the same direction and to change the amount of power applied to the phase modulators in opposite directions so as to change the length of each optical path in a different direction. As a result, the relationship between the changes in the amount of power applied to the modulators and the resulting changes in the phase of light beams passing through the device becomes substantially linear.
Description
The invention relates to optical system and two structures of selecting optical path lengths of change that comprise the element of the light path that forms two or more transmitting beam, and relevant for the method that changes optical path length.If along the optic path light beam of two selections, and the length variations of each light path, the phase place of each light beam will be changed so.
Such optical system can comprise the light path of two different lengths that combine abreast.If beam Propagation is to (front portion) junction of two light paths, this light beam will be divided into two beam components, and one of them will be along the transmission of one of parallel light path, and another will be along another parallel optic path.These two beam components will meet in another (rear portion) junction of two light paths.Since two beam components the optical path length difference of process, therefore when they meet at the combined downstream place, will have phase differential between two beam components.Light beam is bonded to each other in the mode that depends on the phase place extent and interferes.
By adopting a kind of device that is called phase converter to change optical path length in the transparent medium, be well-known thereby change along the phase place of the light beam of optic path.This device can be the electronics integrated device such as PIN diode, comprises the heavy doped region of adjoining with light path (be respectively n mix up with p mix up).By electric current is applied to PIN diode, charge carrier is injected into the adjacent area that transparent medium forms light path, so that change the refractive index of light path in this zone.This variations in refractive index causes the variation of optical path length effectively.The variation of this optical path length causes along the variation of the phase place of the light beam of optic path.
Integrating passive or active silicon insulation (SOI) waveguide of forming light path have application widely.The active integrated optical element that is coupled in the waveguide can be based on phase converter, all modulators of PIN diode as described above.Many integrated optical devices, for example diffractometer, switch and amplitude fading device can be made by this integrated phase converter structure.When phase converter is coupled on the light path of the optical system that has two light paths as described above, can change the length difference of two light paths.Therefore change the interference pattern of two light beams.
Most phase converter, for example above-described PIN diode phase converter all requires to adopt current driver.Because at the current response characteristic of most phase converter, optical path length changes and the variation of phase place is the nonlinear function of drive current.And owing to inject the light scattering that the charge carrier of light path material causes, amplitude modulation(PAM) also takes place in the light beam that transmits by described light path part, and described light path part is coupled on the phase converter that comprises a PIN diode.
The phase converter of another kind of type is hot phase converter.In such modulator, voltage is applied on heating or the cooling device, the temperature of change material makes along the phase change of the light beam of optic path.For above-described PIN diode type phase converter, phase change is the nonlinear function of the voltage that applies.
The integrated optics system that comprises phase converter is applied in such as in the sensor application, and sensor-based system relies on phase converter demodulation or processing signals here.Any non-phasic property of phase converter just reappears at the output terminal of sensor-based system like this.Therefore, the non-linear accuracy that directly influences sensing system of the phase converter of prior art.In prior art system, must adopt complicated linearizer so that remedy this defective.
Because the character of some phase converter, such as previously described PIN diode phase converter, drive current always only flows along a direction in modulator.Therefore, these phase converters only can be driven in one direction, and can make electric current cross at the both direction upper reaches phase converter standard recommend that method of operating normally can not realize.Active optics system such as interferometer and switch comprises two light paths, and uses phase converter on one of two light paths, so as to change two between the light path optical path difference (OPD) thus change the optical characteristics of system.Phase converter can be coupled to any one light path, so that the OPD of system is changed similarly influence of generation.Therefore, in such interferometer or switch, only adopt a phase converter usually.
Another phase converter can be added on another light path of system.Yet because the characteristic of phase converter, each phase converter produces similar influence to associated light path, that is when increasing drive current, it makes optical path length reduce, otherwise when reducing drive current, makes the optical path length increase.The result is in known system, and the variation of the light path that phase converter causes is cancelled out each other basically.Therefore in the optical system of existing use another one phase converter, it is connected with first phase converter usually and be used as standby phase converter on identical light path.
The purpose of this invention is to provide a kind of optical system: comprise forming two or more elements that are used for the light path of transmitting beam, and have the improvement structure that is used to change optical path length, so that change along the phase place of the light beam of optic path.
According to one aspect of the present invention, optical system comprises the element of at least two light paths of formation and is used to change two structures of selecting optical path length, select light path to comprise two phase converters for described two, each phase converter is coupled on one of selected light path, with a drive system, be used for power is applied on the phase converter so that drive them and be used for changing in opposite direction the power that is applied on the phase converter along identical direction, so that change the length of each light path along different directions.
The quantity of power that changes in opposite direction that is applied on the phase converter preferably equates.
The quantity of power that is applied on the phase converter can change simultaneously or continuously.
According to another aspect of the present invention, the method of two optical path lengths of a kind of change is provided, each light path comprises a phase converter, this method comprises the steps: power is applied on two phase converters so that drive phase converter in the same direction, change the quantity of power that is applied on the phase converter in opposite direction, so that change the length of each light path along different directions.
If light beam is selected optic path along each, when the length of each light path changes, phase shift will take place in each light beam.Usually, put on that quantity of power on the phase converter that is coupled in the light path changes and be non-linear along the relation between the phase change that light beam produced of optic path.The phase converter of structure and for phase converter applies the structure of power above adopting is combined the phase change of light beam, has eliminated non-linear basically.As a result, be applied to that quantity of power on the phase converter changes and the light beam phase change that produced between relation to become be linear basically.
Change two systems of selecting the structure of optical path lengths at the element that comprises at least two light paths of formation and being used for, select light path to comprise two phase converters for described two, each phase converter is coupled on one of selected light path, the objective of the invention is to drive phase converter along identical direction, in opposite direction the amount of any one change in the electric current, voltage or the quantity of power that are applied on the phase converter, each all in the identical time interval, makes with respect to the non-linear difference minimum that is applied to electric current identical on the phase converter, voltage or variable power light beam phase change.
Be applied to without any power under the condition of any phase converter, the length of the light path on transmitting beam institute edge can be identical or different.Under latter event, be called light path and have initial light path difference (OPD
0).
Has non-zero OPD in light path according to the present invention
0Optical system in, can utilize above-mentioned technology to change the OPD of system, promptly improve and reduce the power that is applied on another phase converter when being applied to a power on the phase converter.Two phase converters produce opposite influence to the OPD of system, and these influences will be superimposed and produce total POD and change.For given optical path change scope, total this will double the variation of OPD, thereby double total phase change, perhaps change for the OPD that requires, the variable power scope will be reduced to half, be no more than OPD as long as cause the variable power that OPD changes
0
Change along opposite direction owing to be applied to two quantity of power on the phase converter, the length that is coupled to the light path of one of phase converter will increase and the length that is coupled to the light path on another phase converter will reduce.If two light beams made up afterwards, such as in interferometer, the phase change of two light beams just is superimposed.By the phase change in two light beams is superimposed, be applied to quantity of power on each phase converter change with along any non-linear will being cancelled basically between the respective phase variation of the light beam of the optic path that is coupled with phase converter.
To reduce because any amplitude modulation(PAM) in the light beam that phase converter work causes by the structure that changes the light beam phase place in opposite direction.
The phase converter of top indication can be the type that comprises PIN diode.In this structure, change the electric current that is applied to PIN diode so that change the length of light path.
Perhaps, phase converter can be known hot phase converter type.In this structure, change the voltage that is applied on the phase converter so that change the length of light path.
In of the present invention optimizing structure, wherein phase converter is above-mentioned PIN diode type, and before the electric current in changing two phase converters, the initial current of first phase converter of flowing through is zero, and the initial current of second phase converter of flowing through is the maximal value of a selection.Along the phase change that is coupled to the light beam of the optic path on the phase converter electric current in first phase converter to be increased a selected amount in order causing, the electric current in second phase converter to be reduced identical selected amount.This increase and attenuating can simultaneously or be carried out continuously.In either case, when two electric currents change with opposite direction, produce the total phase change that requires between two light beams.If with the combination of two light beams, so total phase change will be the phase change sum of each light beam after the phase change.As a result, change for given electric current, total phase change will double.
Should be appreciated that electric current in the phase converter with non-zero initial current value can not be reduced to is lower than initial current value.
Because in above-mentioned optical system and power application structure, with regard to variable power, always drive two phase converters in opposite direction, so being called, this structure is operated in push pull mode, even in fact the driving of two phase converters is equidirectional.Therefore claim that described this structure is " standard is recommended " power application structure.By utilizing this structure, the overall accuracy of optical system has improved widely such as in sensor application.
In order to be more readily understood the present invention, with reference to the accompanying drawings, only so that formal description is of the present invention for example
Embodiment, wherein:
Fig. 1 is the synoptic diagram of current-voltage (I/V) characteristic of PIN diode phase converter,
Fig. 2 is the schematic diagram of Mach-Zehnder interferometer, and this interferometer comprises two by the phase converter that drives according to power drives structure of the present invention,
Fig. 3 is the circuit theory diagrams of the power drives structure of the foundation phase converter of the present invention described among Fig. 2,
Fig. 4 describes the phase modulation (PM) of using two phase converters according to the present invention shown in Fig. 2 to produce,
Fig. 5 describes the amplitude modulation(PAM) that uses two phase converters according to the present invention shown in Fig. 2 to produce,
Fig. 6 describe record in the test according to phase modulation (PM) of the present invention,
Fig. 7 describe record in the test according to amplitude modulation(PAM) of the present invention, and
Fig. 8 is described in two light paths that do not have the initial light path difference, uses the phase modulation (PM) according to phase converter generation of the present invention shown in two Fig. 2.
With reference to figure 1, this figure explanation applies the voltage V that is higher than threshold value, just has electric current I to flow through the PIN diode phase converter.Diode can only forward bias so that electric current is injected light path, thereby change the concentration of free carrier.Refractive index change delta n in the light path is the function of carrier concentration (being changed by drive current) and the light beam wavelength propagated along light path.The changes delta L of optical path length is directly proportional with refractive index change delta n and optical path length L in phase converter.
ΔL=Δn*L (1)
It should be noted that Δ n is a negative value for electric current changes delta I.
Be based on principle of interference because comprise the most of active optics system of phase converter, in the following description with interferometer as an example.
A specific embodiment of the present invention of describing is based on the active optics system that comprises two light paths.Light path begins to have different length, that is OPD
0Non-vanishing.System comprises two PIN diode phase converters at least.
With reference to figure 2, shown Mach-Zehnder interferometer is the simplest situation of embodiment, comprises two light path P that connect side by side
1, P
2Two light paths have different length L
1, L
2, and each light path comprises a phase converter M
1, M
2, be used to change L
1, L
2Value.Input light path ^ is connected to light path P
1, P
2A node, and output light path P
4Be connected to light path P
1, P
2Other node.At output light path P
4In light beam output (density) have common form:
A+B*COS(φ
d) (2)
φ wherein
dBe light path P
1, P
2In segment beam between optical phase difference φ
d=2 π * OPD/ λ, wherein λ is a wavelength, and
OPD=ABS(L
1-L
2)=ABS(OPD
0+ΔL
1-ΔL
2) (3)
Wherein, OPD
0Be the initial OPD of system, that is without any the initial value under the situation of electric current, and Δ L
1With Δ L
2Be light path P
1And P
2Length variations.
Similarly, the OPD with drive current is changed to:
ΔOPD=ABS(OPD
0+ΔL
1-ΔL
2)-OPD
0 (4)
Wherein ABS (...) refer to the mould of absolute value of its variable.
Can find out from expression formula (4), as just two phase converters of parallel drive and Δ L simply
1Equal Δ L
2The time, the OPD that then produces zero (or near zero) changes, and therefore this method can not be used for obtaining ideal results.Yet, when the drive current by two phase converters changes in the opposite direction with pseudo-push pull mode, as described below with reference to Fig. 4, Δ L
1With Δ L
2Change in the opposite direction, but variable quantity is identical, that is Δ L
1=-Δ L
2, so the OPD variation is:
ΔOPD
max-ΔOPD
min=2*ABS(ΔL
1,max)=2*ABS(ΔL
2,max) (5)
Wherein, Δ OPD
Max=Δ L
1, max, Δ OPD
Min=-Δ L
2, max
The circuit theory diagrams of current drive system shown in Figure 3 are designed to drive phase converter M with accurate push pull mode
1, M
2Do not resemble adopt that different direction of current drives a load (device) recommend drive system usually, shown Driving Scheme becomes to drive to be had two phase converters of same current direction and changes electric current in the phase converter.Because the characteristic of PIN diode phase converter, the drive current of each modulator can not be reverse.More particularly, Driving Scheme become one in the phase converter the electric current change direction and the electric current in another phase converter change in the opposite direction.Shown in driving in, operational amplifier U1:D is used for being provided with the position of midpoint potential.On this position, two phase converters have identical drive current.This set has also been determined maximum operating range I
m, it is a constant.Operational amplifier U1:A is used as input voltage signal V
InputImpact damper.Recommend effect by operational amplifier U1:B and U1:C realization standard.As input voltage V
InputDuring increase, the output of U1:C increases with the speed the same with the output changing down of U1:B.Transistor Q1 and Q2 form the basis of current driver, and driver produces and input voltage V
InputProportional drive current.
Though operational amplifier U1:A to U1:D can be four independent operational amplifiers, in structure shown in Figure 3, all four amplifiers are preferably formed on the chip.I/O for drive system will produce stable more and symmetrical more result like this, and reduce the needed space of drive system.So also reduce the radiation level that is produced, because circuit is driven with constant load,
In the most preferred embodiment of the accurate push-pull method of utilizing drive systems shown in Figure 3 optical system shown in Figure 2, beginning is electric current I
1=0 and I
2=I
mBe applied to the first and second light path P of the system of being positioned at respectively
1, P
2In phase converter M
1, M
2On.Subsequently, utilize the drive system among Fig. 3, phase converter M
1In electric current I
1Increase an expectation value, and phase converter M
2In electric current I
2Reduce identical value, so that another phase converter M
2In electric current always satisfy relations I
2=I
m-I
1Perhaps, this process can similarly compare I from different initial currents
1/ I
2Beginning, but it always comprises a fixing current constant I
m
Shown in Fig. 4 is the result of calculation of electric current-optical path length variation characteristic, is to adopt above-mentioned optical system and standard to recommend drive system to change two phase converter M
1, M
2In electric current obtain.The optical path length changes delta L of the single light path of curve shows among Fig. 4
1, Δ L
2And the combined optical path length variations Δ OPD that is produced depends on drive current.The result shows, total the linearity that the optical path length of the light beam of realizing by accurate push-pull system relevant with two phase converters changes is fine, even the optical path length that each phase converter causes variation linearity for drive current is very poor.This can describe by analytical calculation.As phase converter M
1Drive current I
1From I
1=0 changes to maximum current I
1=I
mThe time, according to accurate push-pull principle, phase converter M
2In electric current will be from I
2=I
mChange to I
2=0.
Curve illustrates I
1Be increased to I from 0
m, while I
2From I
mBe reduced to 0.In this electric current change procedure, as shown in L
1Increase (Δ L
1) and L
2Reduce (Δ L
2).OPD is from initial value OPD as shown in the figure
0-Δ L
2Change to OPD
0+ Δ L
1
Suppose optical path length changes delta L
1With modulator M
1In electric current I
1Between relation be para-curve, i.e. Δ L
1=a+b*I
1+ c*I
1 2(6) wherein, a, b and c are constant coefficients, and their value is fixed according to the characteristic of phase converter.Coefficient a is necessary for 0, because work as electric current I
1Equal 0 o'clock light path length variations Δ L
1Be 0.Simultaneously, phase converter M
2In optical path length changes delta L
2And electric current I
2To satisfy following equation: Δ L
2=a+b*I
2+ c*I
2 2(7) owing to accurate push-pull configuration, I
2≡ I
m-I
1Here I
mIt is the constant value of adjusting according to circuit.For each phase converter, it is generally equal to maximum drive current.Like this, we just have Δ L
2=a+b* (I
m-I
1)+c* (I
m-I
1)
2(8) total OPD variation of system is: Δ OPD=Δ L
1-Δ L
2=-(b*I
m+ c*I
m 2)+2 (b+c*I
m) * I
1(9) this and electric current I
1Variation linear.The result is recommended between phase change that drive system produces and the drive current by standard and is extraordinary linear relationship (as shown in Figure 4).
When drive current changes to I from 0
mThe time, we are easy to draw maximum OPD from equation 9 and change
Δ OPD
Min=-(b*I
m+ c*I
m 2The Δ L of)=-
1, max, I
1=0 o'clock,
ΔOPD
max=b*I
m+c*I
m 2=-ΔL
1,max,I
1=I
m (10)
Maximum phase is changed to like this: Δ φ
D, max=φ
D, max-φ
D, min=2* φ
1, max=2* Δ φ
2, max=2 π * 2 Δ L
1, max/ λ=2 π *, 2 Δ L
2, max/ λ (11)
This shows that adopting accurate maximum phase variation of recommending two phase converters of drive systems is the twices that only comprise the maximum magnitude of the system of a phase converter.
Similarly, can calculate amplitude modulation(PAM) and being illustrated among Fig. 5.In Fig. 5, all curves that illustrate all are normalized to power ratio 1 in their maximum of points.As mentioned above, the phase modulation (PM) of the light beam relevant with phase converter is to be caused by the electric current that is injected in the light path.When electric current is injected in the light path 33, charge carrier and the photon effect that forms in the waveguide of light path also cause light scattering, and this causes loss of light intensity or amplitude modulation(PAM) that optical system is certain.Amplitude modulation(PAM) is a negative effect of phase converter, should reduce as much as possible.Usually, the important tolerance of amplitude modulation(PAM) is the ratio for amplitude with the amplitude peak of given electric current (or giving phase bit).Use two amplitude modulation(PAM)s that utilize accurate phase converter of recommending drive system control to cause more complicated more, therefore calculate (shown in Figure 5) and be based on the data that are similar to very much true phase converter characteristic than phase modulation (PM).Indicate shown in the curve of power 1 is if the amplitude modulation(PAM) when only driving first phase converter, indicating shown in the curve of power 2 is amplitude modulation(PAM) when only driving second phase converter, shown in the curve of recommending power is amplitude modulation(PAM) when adopting accurate push-pull technique to drive two phase converters and indicate.The accurate drive system of recommending produces less amplitude modulation(PAM) shown in the figure.
Experiment show above calculating.Fig. 6 illustrates the test result of phase modulation (PM), and shown in Fig. 7 is the test result of amplitude modulation(PAM).
The optical system of comprehensive utilization with two phase converters recommended the result that drive system is carried out phase place and amplitude modulation(PAM) with the standard that is used for controlling phase converter as mentioned above, can be summarized as follows:
Total phase change is the phase place sum of the phase change of two phase converters generations.
Though because the phase change that single modulator produces departs from desirable para-curve response, phase change is not an ideal linearity, the linearity of phase change has greatly improved.Usually, from the angle of phase change linearity degree, probably improve an order of magnitude or slightly little.
Described optical system can be used on active silicon-on-insulator (SOI) optical devices, and it comprises two light paths, based on principle of interference work, such as switch or amplitude fading device.It also can be used on the interferometer, such as is used for demodulation or handles signal from sensor.Optical interferometry is to be widely used in the technology that pin-point accuracy is measured.For these application, the performance of phase converter is depended in system's accuracy.Improve the linearity or reduce amplitude modulation(PAM) and make it possible to reach high accuracy.
Above-mentioned advantage causes following result in application:
Can be applied to require big phase change scope such as in interference sensor.
Phase change scope for fixing requires less (only about half of) drive current variations.For switch, this means that the pulse current of on/off reduces by half, this makes easier raising actuating speed and reduce noise to other circuit.
When using aforesaid driving circuit, no matter state of optical system how, it is constant that standard is recommended the electric current that control system obtains from power supply.Therefore described control device reduces the electric radiation of system, thereby makes it possible to the remainder of driving circuit and device packaging together.
As the substitute of PIN diode phase converter, above-mentioned standard is recommended drive system and can be used with hot phase converter.Because it is hot phase converter arranged, relevant with the thermal power in being applied to light path along the phase change of the light beam of the optic path that wherein is connected with hot phase converter.Because thermal power and electric current is square proportional, so the phase modulation (PM) general type is a*I
2, that is have parabolic shape.This shows that it is highly nonlinear that phase place changes with electric current, particularly when electric current is big.If yet optical system (such as interferometer) adopts the above-mentioned two hot phase converter that standard is recommended drive system that has, and the height of eliminating single phase converter effectively is non-linear, and produces linear current-responsive.
Although should also be noted that the invention described above most preferred embodiment, the present invention also can with do not have initial OPD (that is OPD
0=0) active optics device uses together.The key distinction is in this case, according to equation 4, adopt this method identical with the scope of a phase converter with the phase change scope that device can obtain, rather than the scope sum (see figure 8) of two phase converters, yet, except this restriction, this structure still can realize other all advantages of the present invention, such as improving nonlinearity, reduces amplitude modulation(PAM) effectively, the power drives load is constant, and needs small electric rheologyization (reducing by half) for given phase range.
As what point out above, though described system and driving method may be used on the device of other form, optical system preferably is produced on silicon-on-insulator (SOI) chip.
Light path preferably is formed at the rib shape waveguide of the upper silicon layer of soi chip, and the PIN diode phase converter is preferably formed on the transverse area of rib shape waveguide.The further details of this waveguide and PIN diode provides in WO95/08787, and its content is included in here for your guidance.
Claims (13)
1. optical system, the element that comprises at least two light paths of formation, with the structures that are used to change two selection optical path lengths, select light path to comprise two phase converters for described two, each phase converter is coupled on one of selected light path and a drive system, is used for power is applied on the phase converter so that drive them along identical direction, change the quantity of power that is applied on the phase converter in opposite direction with being used for, so that change the length of each light path along different directions.
2. optical system as claimed in claim 1, wherein said drive system comprise the device that in opposite direction quantity of power that is applied to modulator is changed equal quantities.
3. optical system as claimed in claim 1 or 2, wherein said drive system comprise that change simultaneously is applied to the device of the quantity of power on the phase converter
4. as claim 1,2 or 3 described optical systems, wherein the light path of two selections has the initial light path difference of non-zero.
5. any one described optical system in the claim as described above, wherein phase converter comprises PIN diode, wherein drive system provides electric current to PIN diode, also comprises being used to change electric current so that change the device of optical path length.
6. as any one described optical system in the claim 1 to 4, wherein phase converter comprises hot phase converter, and wherein drive system provides voltage to phase converter, also comprises being used to change voltage so that change the device of optical path length.
7. any one described optical system in the claim as described above, wherein drive system comprises driving circuit, this driving circuit comprises operational amplifier, operational amplifier is arranged so that when input voltage is applied to driving circuit, and the output of an operational amplifier is to increase with the identical speed of speed that reduces of the output of another operational amplifier.
8. optical system as claimed in claim 7, wherein driving circuit is arranged so that at its duration of work and produces constant drive current.
9. as claim 7 or 8 described optical systems, wherein all operational amplifiers all are arranged on the same chip.
10. any one described optical system in the claim as described above is formed on the silicon-on-insulator chip.
11. optical system as claimed in claim 10, wherein light path comprises the waveguide of rib shape.
12. any one described optical system in the claim as described above forms the part of Mach-Zehnder interferometer.
13. method that changes two optical path lengths, each light path comprises a phase converter, this method comprises the steps: power is applied on two phase converters so that drive phase converter in the same direction, change the quantity of power that is applied on the phase converter in opposite direction, so that change the length of each light path along different directions.
Applications Claiming Priority (4)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US96943497A | 1997-11-12 | 1997-11-12 | |
| US08/969,434 | 1997-11-12 | ||
| GB9810693.3 | 1998-05-19 | ||
| GB9810693A GB2331373B (en) | 1997-11-12 | 1998-05-19 | Optical system and method for changing the lengths of optical paths and the phases of light beams |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN1285931A true CN1285931A (en) | 2001-02-28 |
Family
ID=26313706
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN 98813074 Pending CN1285931A (en) | 1997-11-12 | 1998-11-12 | Optical system and method for changing the lengths of optical paths and the phases of light beams |
Country Status (5)
| Country | Link |
|---|---|
| EP (1) | EP1031065A1 (en) |
| JP (1) | JP2001523012A (en) |
| CN (1) | CN1285931A (en) |
| CA (1) | CA2309815A1 (en) |
| WO (1) | WO1999024867A1 (en) |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103402421A (en) * | 2011-02-04 | 2013-11-20 | 海德堡工程有限责任公司 | Method and device for the sequential recording of interferometric deep sectional images at different depths, in particular for analysis of the eye |
| CN104125066A (en) * | 2013-04-26 | 2014-10-29 | 美国博通公司 | Methods and systems for secured authentication of applications on a network |
| CN104155780A (en) * | 2013-05-14 | 2014-11-19 | 鸿富锦精密工业（深圳）有限公司 | Electro-optic modulator |
Families Citing this family (11)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP4519248B2 (en) * | 2000-03-14 | 2010-08-04 | 富士通株式会社 | Optical device with optical waveguide |
| GB2365987B (en) * | 2000-08-11 | 2004-04-28 | Bookham Technology Plc | An electro-optic device |
| US6493502B1 (en) | 2001-05-17 | 2002-12-10 | Optronx, Inc. | Dynamic gain equalizer method and associated apparatus |
| US6608945B2 (en) | 2001-05-17 | 2003-08-19 | Optronx, Inc. | Self-aligning modulator method and associated apparatus |
| US6526187B1 (en) | 2001-05-17 | 2003-02-25 | Optronx, Inc. | Polarization control apparatus and associated method |
| WO2002093218A1 (en) * | 2001-05-17 | 2002-11-21 | Optronx, Inc. | Polyloaded optical waveguide devices |
| US6646747B2 (en) | 2001-05-17 | 2003-11-11 | Sioptical, Inc. | Interferometer apparatus and associated method |
| US6625348B2 (en) | 2001-05-17 | 2003-09-23 | Optron X, Inc. | Programmable delay generator apparatus and associated method |
| GB2378524A (en) * | 2001-08-08 | 2003-02-12 | Bookham Technology Plc | Intergrated optic device |
| US8098968B2 (en) * | 2007-09-04 | 2012-01-17 | International Business Machines Corporation | Silicide thermal heaters for silicon-on-insulator nanophotonic devices |
| CN112485860A (en) * | 2019-09-12 | 2021-03-12 | 源杰科技股份有限公司 | Electro-optical modulation device |
Family Cites Families (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB2230616B (en) * | 1989-03-30 | 1993-07-14 | British Telecomm | Silicon bipolar phase modulator |
| GB2302738B (en) * | 1995-06-28 | 1999-03-03 | Northern Telecom Ltd | Semiconductor modulator with a shift |
-
1998
- 1998-11-12 WO PCT/GB1998/003404 patent/WO1999024867A1/en not_active Application Discontinuation
- 1998-11-12 EP EP98954575A patent/EP1031065A1/en not_active Withdrawn
- 1998-11-12 CN CN 98813074 patent/CN1285931A/en active Pending
- 1998-11-12 JP JP2000519808A patent/JP2001523012A/en active Pending
- 1998-11-12 CA CA002309815A patent/CA2309815A1/en not_active Abandoned
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103402421A (en) * | 2011-02-04 | 2013-11-20 | 海德堡工程有限责任公司 | Method and device for the sequential recording of interferometric deep sectional images at different depths, in particular for analysis of the eye |
| CN103402421B (en) * | 2011-02-04 | 2016-01-20 | 海德堡工程有限责任公司 | For taking the interferometry degree of depth cross-section image of different depth continuously, analyzing the method and apparatus of eyes |
| CN104125066A (en) * | 2013-04-26 | 2014-10-29 | 美国博通公司 | Methods and systems for secured authentication of applications on a network |
| CN104155780A (en) * | 2013-05-14 | 2014-11-19 | 鸿富锦精密工业（深圳）有限公司 | Electro-optic modulator |
Also Published As
| Publication number | Publication date |
|---|---|
| CA2309815A1 (en) | 1999-05-20 |
| EP1031065A1 (en) | 2000-08-30 |
| WO1999024867A1 (en) | 1999-05-20 |
| JP2001523012A (en) | 2001-11-20 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN1285931A (en) | Optical system and method for changing the lengths of optical paths and the phases of light beams | |
| US10678117B2 (en) | Optical phased array (OPA) | |
| US9979489B2 (en) | Optical modulation apparatus, optical transmitter and controlling method for optical modulator | |
| US7977622B2 (en) | Tuning an optical resonator using a feedback signal representing an average DC balanced coding | |
| US6233070B1 (en) | Optical system and method for changing the lengths of optical paths and the phases of light beams | |
| CN102955265B (en) | Optical semiconductor device | |
| CN112180653B (en) | XOR and XNOR logic operation unit based on optical mode | |
| US20080273567A1 (en) | Hybrid waveguide systems and related methods | |
| Jarrahi et al. | Optical switching based on high-speed phased array optical beam steering | |
| US7369714B2 (en) | High-speed electronic carrier-injection modulator based on high-index-contrast Si-waveguide | |
| US7050689B2 (en) | Photonic device with segmented absorption design | |
| US7064891B2 (en) | Optical wavelength converter with a semiconductor optical amplifier | |
| Rostami | Piecewise linear integrated optical device as an optical isolator using two-port nonlinear ring resonators | |
| Jarrahi et al. | High-speed optical beam-steering based on phase-arrayed waveguides | |
| US6529674B2 (en) | Optical devices employing an optical thresholder | |
| CN112729604B (en) | Fano resonance three-dimensional sensing device based on double-ring generation | |
| JP3395360B2 (en) | Light modulation element | |
| Catuneanu et al. | Design considerations and constraints in silicon based optical on-board interconnects for short range communications | |
| Lin et al. | On-chip optical waveguide visible-light power detector based on photothermal effect of PPy/SU-8 photopolymer | |
| Gu et al. | Prismatic coupling structure for intrachip global communication | |
| US6906853B2 (en) | Systems and methods for wavelength conversion using photonic bandgap shifting | |
| JP2812494B2 (en) | Driving method of optical functional element | |
| CN114296292A (en) | Logic gate based on single-ring embedded resonant cavity optical system | |
| JP6659520B2 (en) | Optical transmitter | |
| Knupfer et al. | Monolithic waveguide-based smart pixel operating at 120 Mb/s |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C06 | Publication | ||
| PB01 | Publication | ||
| C10 | Entry into substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| C02 | Deemed withdrawal of patent application after publication (patent law 2001) | ||
| WD01 | Invention patent application deemed withdrawn after publication |