JP2014182259A - Wavelength multiplexer/demultiplexer and optical integrated circuit device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make it possible to achieve both the restriction of element size increase and spectrum flatness improvement and to enable the monitoring of the output of light, in terms of a wavelength multiplexer/demultiplexer and an optical integrated circuit device.SOLUTION: An add drop type ring resonator asymmetrical in optical coupling efficiency between the add side and drop side is coupled to the arm waveguide (relatively short in optical length) of a first delay Mach-Zehnder interferometer in which optical couplers are formed on the input terminal side and output terminal side such that two arm waveguides of different optical lengths are located opposite each other. A second delay Mach-Zehnder interferometer of 1/2 of optical length difference of the first delay Mach-Zehnder interferometer and a third delay Mach-Zehnder interferometer are cascade coupled via the one of the optical couplers.

Description

  The present invention relates to a wavelength multiplexer / demultiplexer and an optical integrated circuit device. For example, the present invention relates to a wavelength multiplexer / demultiplexer and an optical integrated circuit device used in optical communication and an optical interconnect.

  In recent years, Si photonics has attracted attention as a promising technology for large-capacity interconnects. The main advantage of the Si photonics technology is that high-density integration is possible because the cross-sectional area of the optical wiring is several hundred nm square. In addition, it can be expected that transmission capacity per optical wiring can be improved by wavelength division multiplexing (WDM) within the Si chip.

  In order to transmit and receive WDM optical signals within the Si chip, a wavelength multiplexer / demultiplexer is required along with a light source, an optical modulator and a light receiver. This wavelength multiplexer / demultiplexer multiplexes / demultiplexes WDM optical signals as necessary. In this case, the characteristics required for the wavelength multiplexer / demultiplexer include spectral flatness in addition to low loss and low channel deviation.

  As an element structure that satisfies these conditions, a wavelength multiplexer / demultiplexer in which a delayed Mach-Zehnder interferometer (DMZI) is cascade-connected in multiple stages has been reported. US Intel Corporation has reported a DMZI type multiplexer / demultiplexer (see, for example, Non-Patent Document 1).

Here, a 1 × 4 Ch DMZI type wavelength multiplexer / demultiplexer formed by using the prior art will be described with reference to FIG. FIG. 11 is a conceptual plan view of a 1 × 4 Ch DMZI type wavelength multiplexer / demultiplexer formed by using a conventional technique. Two arm waveguides 81 ₁ and 82 ₁ having different optical path lengths are opposed to each other at the input end. The optical couplers 83 ₁ and 84 ₁ are formed on the side and the output end side to form the DMZI 80 ₁ . The arm waveguide 82 ₁ having a long optical path length is a delay waveguide with respect to the arm waveguide 81 _{1 having} a short optical path length.

A wavelength multiplexer / demultiplexer is constituted by a two-stage DMZI in which two DMZIs 80 ₂ and 80 ₃ are cascade-connected to the first stage DMZI 801 ₁ . At this time, the optical path length difference between the two DMZIs 80 ₂ and 80 ₃ is set to ½ of the optical path length difference of the first DMZI 80 ₁ , and the phase shifter 85 ₃ for controlling the phase is provided in one DMZI 80 ₃ . forming a phase difference between two of DMZI80 ₂ relative π / 2 (= λ / 4 ). Incidentally, the phase shifter 85 ₃ are generally simply addition to forming by adjusting the waveguide length, the waveguide width can be formed by changing the tapered shape.

  The wavelength multiplexer / demultiplexer with DMZI having such a two-stage structure can obtain good multiplexing / demultiplexing characteristics, but the spectrum shape becomes a parabolic function, and the spectral flatness cannot be obtained in principle. There is.

To solve this problem, IBM Corporation connects different DMZI optical path length difference to facilitate and optimize the optical coupling ratio k _i of each DMZI, it proposes to obtain spectral flatness (For example, refer nonpatent literature 2). Here, the proposed improved wavelength multiplexer / demultiplexer will be described with reference to FIG.

Figure 12 is a schematic plan view of an improved type wavelength demultiplexer according to the proposed, has for DMZI80 ₁ of the first stage, the optical path length difference to increase and the phase difference from each other than DMZI80 ₁ of the first stage 2 Two DMZIs 80 ₄ and 80 ₅ are connected in series. Also, two DMZI80 _2, 80 respectively optical path length difference to ₃ of the second stage connects the two DMZI80 _6, 80 ₇ with DMZI80 _2, 80 greater than ₃ and the phase difference from each other in the second stage in series. The phase shifter ₈₅ 5, 85 ₇ are formed in the DMZI80 ₅ and DMZI80 _7. Here, spectral flatness is obtained by setting the optical coupling coefficient k of each of the optical couplers 83 _{1 to} 83 ₃ and 84 _{1 to} 84 ₇ as shown in the figure.

  In addition, a spectral resonator can be obtained by optically coupling a ring resonator to an arm waveguide having a shorter optical path length of DMZI to form an all-pass type ring resonator (AP-MRR: All-Pass MicroRing Resonator). (For example, refer to Patent Document 1).

FIG. 13 is an explanatory diagram of a conventional all-pass ring resonator, FIG. 13 (a) is a conceptual plan view, and FIG. 13 (b) is an explanatory diagram of optical output characteristics from an optical coupler. As shown in FIG. 13A, an arm having a short optical path length of a DMZI 90 in which optical couplers 93 and 94 are formed on the input end side and the output end side with two arm waveguides 91 and 92 having different optical path lengths facing each other. A ring resonator 96 is optically coupled to the waveguide 91 to form an AP-MRR. When wavelength multiplexed light including a plurality of wavelengths λ _{1 to} λ ₆ is incident on the input port of the optical coupler 93, the light is distributed from the two output ports of the optical coupler 94 for each channel, and λ ₁ , λ ₃ , λ _5, and so on. Output as λ ₂ , λ ₄ , and λ ₆ .

  Further, as shown in FIG. 13B, the transmission spectrum characteristics are flat for almost all wavelengths.

JP 2000-298222 A

OSA Optics Letters, vol. 33, no. 5, pp. 530-532, March 2008 International Conference OFC / NFOEC, 2010, OWJ3, March 2010

  However, the wavelength multiplexer / demultiplexer shown in FIG. 11 has a problem that spectral flatness cannot be obtained in principle as described above. In addition, although the improved wavelength branching filter shown in FIG. 12 provides spectral flatness, the number of control points of the optical coupling rate k in each optical coupler of each DMZI stage is large, and the number of DMZIs inevitably increases. There is a problem that the element size increases.

  Furthermore, in some cases, it becomes necessary to correct the characteristic deterioration due to deformation accompanying the element processing accuracy. However, in order to correct the characteristic deterioration, it is necessary to monitor the light output. However, in the case of past reports, it is extremely difficult to perform monitoring, which is a problem in practice.

  In addition, the AP-MRR shown in FIG. 13 alone generates a wavelength multiplexed light by combining a plurality of optical signals having different wavelengths, and generates an optical signal for each wavelength by demultiplexing the wavelength multiplexed light. There is a problem that the function as a wavelength multiplexer / demultiplexer cannot be realized. Further, even if the AP-MRRs are cascade-connected, there is a problem that it is very difficult to set conditions for realizing spectral flatness and low crosstalk characteristics.

  Accordingly, it is an object of the wavelength multiplexer / demultiplexer and the optical integrated circuit device to simultaneously suppress the increase in the element size and improve the spectral flatness and to monitor the optical output.

  From one aspect disclosed, a first delay Mach-Zehnder interferometer in which two arm waveguides having different optical path lengths are opposed to each other and optical couplers are formed on an input end side and an output end side, and the relative optical path An add / drop ring resonator optically coupled to a short arm waveguide and cascaded via one optical coupler of the first delay Mach-Zehnder interferometer, the first delay Mach-Zehnder A second delay Mach-Zehnder interferometer, a third delay Mach-Zehnder interferometer, a second delay Mach-Zehnder interferometer, a third delay Mach-Zehnder interferometer, and a third delay Mach-Zehnder interferometer; At least a first phase shifter provided on one side of the delay Mach-Zehnder interferometer, and the optical coupling rate on the add port side of the add / drop ring resonator is 10% of the optical coupling rate to the drop port side Double Wavelength demultiplexer, which is a 0-fold is provided.

  From another viewpoint to be disclosed, a light receiver is connected to the output terminal of each delay Mach-Zehnder interferometer constituting the cascade connection of the wavelength multiplexer / demultiplexer and the wavelength multiplexer / demultiplexer. There is provided an optical integrated circuit device characterized by comprising an optical receiver array formed in this manner.

According to the disclosed wavelength multiplexer / demultiplexer and the optical integrated circuit device, it is possible to monitor the optical output while simultaneously suppressing the increase in the element size and improving the spectral flatness.

It is explanatory drawing of the example of examination before reaching this invention. It is a transmission spectrum characteristic figure of the wavelength multiplexer / demultiplexer of the examination example. It is explanatory drawing of the wavelength multiplexer / demultiplexer of embodiment of this invention. It is a conceptual top view of the wavelength multiplexer / demultiplexer of Example 1 of this invention. It is explanatory drawing of the manufacturing process of the wavelength multiplexer / demultiplexer of Example 1 of this invention. It is a conceptual top view of the wavelength multiplexer / demultiplexer of Example 2 of this invention. It is a notional top view of the optical integrated circuit device of Example 3 of the present invention. It is explanatory drawing of a heater. It is explanatory drawing of the principle of a monitor, and a transmission spectrum characteristic. It is explanatory drawing of the transmission spectrum characteristic of one channel, and the improvement effect of crosstalk. FIG. 3 is a conceptual plan view of a 1 × 4 Ch DMZI wavelength multiplexer / demultiplexer formed by using a conventional technique. FIG. 4 is a conceptual plan view of a proposed improved wavelength multiplexer / demultiplexer. It is explanatory drawing of the conventional all pass type | mold ring resonator.

  Here, with reference to FIG. 1 thru | or FIG. 3, the wavelength multiplexer / demultiplexer of embodiment of this invention is demonstrated. FIG. 1 is an explanatory diagram of a study example before reaching the present invention. Here, the wavelength multiplexer / demultiplexer using the AP-MRR described with reference to FIG. 13 was examined. FIG. 1 is an explanatory diagram of a study example, FIG. 1 (a) is a conceptual plan view of a wavelength multiplexer / demultiplexer of the study example, and FIG. 1 (b) is an explanatory diagram of an anti-resonance condition.

As shown in FIG. 1 (a), to form the AP-MRR by the ring resonator 86 to DMZI80 ₁ of the first stage optically coupled, the DMZI80 _2, 80 ₃ of the second stage cascaded same as conventional It is a structure. In this case, the optical coupling between DMZI80 ₁ and AP-MRR first stage, to avoid the influence of resonance (resonance) which is determined by the size and shape of the ring resonator 86 is anti-resonance must satisfy. That is, as shown in FIG. 1B, it is necessary to match the AP-MRR FSR (Free Spectral Range) with the channel interval and shift the center wavelength λ _MRR by π radians.

Thus, AP-MRR by DMZI80 ₁ and the ring resonator 86 of the first stage and anti Resonance condition is satisfied, as shown in FIG. 2, a flat transmission spectrum characteristic of a box-type rather than the parabolic is obtained, As a result, no excess loss occurs. Here, the channel interval is 400 GHz, which shows the calculation example of the optical coupling efficiency _{k MA} and 0.75.

However, the wavelength demultiplexer having the structure shown in FIG. 1 (a), the constant phase error between the DMZI80 ₁ and the ring resonator 86 by the manufacturing stage occurs, deterioration of the transmission spectrum is unavoidable There is a problem. Furthermore, since all the optical waveguides from the input channel are connected to the output channel, it is extremely difficult to monitor the multiplexing / demultiplexing characteristics. For this reason, when a phase difference occurs, it is not easy to correct the deteriorated transmission spectrum characteristics.

  Therefore, as a result of intensive studies, the present inventor has made the ring resonator coupled to the first stage DMZI an add-drop type ring resonator (AD-MRR: Add-Drop MicroRing Resonator). Settled.

FIG. 3 is an explanatory diagram of the wavelength multiplexer / demultiplexer according to the embodiment of the present invention. Here, it will be described as a 1 × 4 Ch DMZI type wavelength multiplexer / demultiplexer. FIG. 3A is a conceptual plan view of the wavelength multiplexer / demultiplexer according to the embodiment of the present invention, and FIG. 3B is a transmission spectrum characteristic diagram. As shown in FIG. 3A, two arm waveguides 11 ₁ and 12 ₁ having different optical path lengths are opposed to each other to form optical couplers 13 ₁ and 14 ₁ on the input end side and the output end side to form DMZI _{10 1.} Form. The long arm waveguide ₁₂₁ of the optical path length becomes a delay waveguide for short arm waveguide 11 ₁ of the optical path length, channel spacing is defined by the optical path length difference between them.

In the present invention, the ring resonator 16 to the optical path length of the short arm waveguide 11 ₁ a ring waveguide causes optical coupling, optical coupling waveguide 17 on the side of the short arm waveguide 11 ₁ and the opposing optical path lengths Thus, an add / drop type ring resonator is obtained. In this case as well, the anti-resonance condition is satisfied.

Constituting the wavelength demultiplexer in DMZI conventional as well as two DMZI10 _2, 10 ₃ the second stage structure cascaded with respect DMZI10 ₁ of the first stage. At this time, the difference between the optical path lengths of the two DMZIs 10 ₂ and 10 ₃ is ½ of the optical path length difference of the first DMZI _{10 1} , and the phase shifter 15 ₃ for controlling the phase is provided in one DMZI 10 ₃ . forming a phase difference between two of DMZI10 ₂ relative π / 2 (= λ / 4 ). Incidentally, the phase shifter 15 ₃ are generally simply formed by adjusting the waveguide length.

Here, the optical coupling efficiency between the arm waveguides 11 ₁ short optical path length and the ring resonator 16, i.e., the add port side of the optical coupling efficiency k _MA and waveguide 17 and the optical coupling efficiency between the ring resonator 16, i.e., The optical coupling efficiency k _MB on the drop port side is set asymmetrically.

The optical coupling efficiency k _MA is set to 65% or more, the optical coupling efficiency k _MB is set to 6.5% or less, and k _MA >> 10 k _MB is set. In the case of k _MA <10 k _MB , the extraction of light to the drop port is too large, the excess loss increases, and the flatness of the transmission spectrum characteristic is lost. On the other hand, it is desirable to set k _MB larger than 3%. If k _MB is too small, the amount taken out to the drop port side is too small to obtain a sufficient monitor output.

FIG. 3B is a transmission spectrum characteristic graph when the channel interval is set to 400 GHz, k _MA = 0.75 (75%), and k _MB = 0.05 (5%). It can be seen that substantially the same spectral flatness as the transmission spectral characteristics can be obtained. Further, the excess loss associated with the AD-MRR is only about 0.05 dB, and hardly affects the multiplexing / demultiplexing characteristics.

  In this way, an add / drop ring resonator is optically coupled to the DMZI of the first stage to form a cascade-connected wavelength multiplexer / demultiplexer, thereby achieving a small size, low loss and flat transmission spectrum characteristics. And waveform correction by monitoring is also possible.

  For monitoring, a light receiving element such as a photodiode may be provided at the output end of the waveguide 17. In order to correct the waveform by monitoring, the refractive index of the ring resonator 16 may be changed, heated, irradiated with ultraviolet rays, or current is injected into the core layer of the ring waveguide. You may do it.

  When heating the ring resonator 16, a heater pattern using Ti or the like may be provided on the ring resonator 16, and the pattern shape may be a meandering pattern like a normal heater, or A pattern having a shape along the shape of the ring resonator 16 may be used.

In addition, in the case of FIG. 3A, a 1 × 4 Ch configuration is shown, but a third stage DMZI or the like is further cascade-connected to the subsequent stage of the second stage, so that a multi-stage wavelength multiplexer / demultiplexer can be obtained. good. In that case, the amount of phase shift in the phase shifter 15 ₃ provided in each stage, it is necessary to set to evenly divide the channel spacing.

Further, by providing a light receiving element such as a photodiode at each output end of DMZI in the final stage, a passive type optical integrated circuit device can be configured. Each waveguide structure generally uses single crystal silicon as a core layer and SiO ₂ as a cladding layer.

Next, the wavelength multiplexer / demultiplexer according to the first embodiment of the present invention will be described with reference to FIGS. FIG. 4 is a conceptual plan view of the wavelength multiplexer / demultiplexer according to the first embodiment of the present invention. As shown in FIG. 4, two arm waveguides 21 ₁ and 22 ₁ having different optical path lengths are opposed to each other to form optical couplers 23 ₁ and 24 ₁ on the input end side and the output end side to form DMZI 20 ₁ . . Here, if the wavelength of 1.55μm near to the channel spacing and 400 GHz, and 90μm of DMZI20 ₁ of the optical path length difference _{L D1.}

The ring resonator 26 for the short arm waveguide 21 ₁ of the optical path length composed of a ring waveguide causes optically coupled add-drop side optically coupled to waveguide 27 in which the short arm waveguide 21 ₁ and the opposing optical path lengths Type ring resonator. In this case, the circumferential length L _M1 of the ring resonator 26 is set to 180 μm.
In this case as well, the anti-resonance condition is designed, and k _MA = 0.75 and k _MB = 0.05 are set.

  In order to set such an optical coupling rate, a directional coupler is formed and the interval between the coupling waveguides is adjusted. When the coupling waveguide length is 14 μm, a desired optical coupling rate is obtained. The gaps (Gap) between the coupling waveguides for obtaining the above are 0.16 μm and 0.35 μm, respectively.

Also, to configure two DMZI20 _2, 20 ₃ and 1 × 4Ch wavelength demultiplexer in DMZI the second stage structure by cascade-connected to DMZI20 ₁ of the first stage. At this time, the two DMZI20 _2, 20 optical path length difference of _3, and 45μm, respectively, DMZI20 ₃ phase shifter 25 ₃ provided DMZI20 ₂ against [pi / 2 in which the optical path length slightly longer (= λ / 4) The phase difference is formed.

Next, a manufacturing process of the wavelength multiplexer / demultiplexer according to the first embodiment of the present invention will be described with reference to FIG. 5. Here, a cross-sectional structure of one waveguide portion will be described. First, as shown in FIG. 5A, an SOI substrate in which a single crystal silicon layer 33 having a thickness of 0.25 μm is provided on a silicon substrate 31 with a SiO ₂ film 32 interposed therebetween is prepared.

Next, as shown in FIG. 5B, a resist pattern 34 having a waveguide stripe structure having a width of 0.48 μm is formed by an exposure process, and dry etching is performed to form a core layer 35 to obtain a channel waveguide structure. To do. Next, as shown in FIG. 5C, after removing the resist pattern 34, a SiO ₂ film 36 is deposited on the entire surface to form a cladding layer.

  As shown in FIG. 5D, a rib waveguide structure may be formed by leaving a slab portion 37 having a height of 0.05 μm when the core layer is formed. Thus, if the slab part 37 is formed on both sides of the core layer 35, the refractive index of the waveguide can be changed by current injection.

  As described above, in the first embodiment of the present invention, the ring waveguide is optically coupled to the DMZI of the first stage to form the add / drop type ring resonator. Spectral characteristics can be compatible and monitoring is also possible.

  Next, the wavelength multiplexer / demultiplexer according to the second embodiment of the present invention will be described with reference to FIG. 6. The wavelength multiplexer / demultiplexer according to the second embodiment is the output of the wavelength multiplexer / demultiplexer according to the first embodiment. A third stage DMZI is cascade-connected to the port.

Figure 6 is a schematic plan view of the wavelength demultiplexer of the second embodiment of the present invention, the DMZI20 _2, 20 each of _three third stage of the second stage wavelength division multiplexer of Example 1 DMZI20 the _{4-20 7} cascade connection. In this case, the optical path length difference DMZI20 ₄ ~20 ₇ of the third stage is 1/2 of 22.5μm of DMZI20 _2, 20 ₃ of the optical path length difference of the second stage. The phase shifter 25 ₅ provided in DMZI20 ₅ is such that the phase difference of + [pi / 2 with respect to DMZI20 ₄ is formed.

The phase shifter 25 ₆ provided on DMZI20 _6, the phase difference is set to be - [pi] / 4, the phase shifter 25 ₇ provided on DMZI20 _7, the phase difference is set to be + π / 4.

  Thus, by setting, it is possible to configure eight channels whose wavelengths are evenly shifted at a channel interval of 400 GHz. In the case of cascade connection in more stages, the optical path length difference is set to 1/2 in turn, and the phase difference by each phase shifter is set to be subdivided by ± 1/2 sequentially.

  Next, an optical integrated circuit device according to Embodiment 3 of the present invention will be described with reference to FIGS. FIG. 7 is a conceptual plan view of an optical integrated circuit device according to a third embodiment of the present invention, in which a photodiode is connected to each output terminal of the wavelength multiplexer / demultiplexer according to the first embodiment. Also, here, a heater is provided on the ring waveguide to change the refractive index, thereby enabling phase control.

As shown in FIG. 7, photodiodes 40 ₁ to 40 ₄ are connected to the output ports of the second stage DMZIs 20 ₂ and 20 ₃ , and the monitoring photodiode is also connected to the output terminal of the waveguide 27 on the drop port side. 40 ₅ is provided. In this case, the photodiodes 40 ₁ to 40 ₅ may be formed by growing a germanium layer so as to be bad-joint coupled to the core layer of each output port to form a photodiode having a pin structure. In addition, a heater 50 is provided on the ring resonator 26 so as to overlap projection.

8A and 8B are explanatory views of the heater, FIG. 8A is a schematic plan view, and FIG. 8B is a schematic cross-section along the alternate long and short dash line connecting AA 'in FIG. 8A. FIG. As shown in the figure, a Ti pattern 51 is formed on the SiO ₂ film 36 to be a clad layer, and the entire surface is again covered with the SiO ₂ film 52. Then, an Al contact 53 is provided at the end of the Ti pattern 51 to provide a heater. 50.

Thus, use of the photodiode 40 ₅ connected to the drop port side as the wavelength control monitor, even if unintended phase shift between the DMZI20 ₁ and the ring resonator 26, quantitatively monitoring the deviation it can. Further, by controlling the amount of current flowing through the heater 50 based on the monitored result, it is possible to compensate for the phase shift and correct the deteriorated spectral characteristics. In addition, when temperature rises by heating, a refractive index will become high and a wavelength will shift to a long wavelength side.

FIG. 9 is an explanatory diagram of the principle of the monitor and transmission spectrum characteristics. As shown in FIG. 10 (a), the transmission spectral characteristics are greatly deteriorated according to the phase shift in the manufacturing process. In this case, the degree of characteristic deterioration may be observed value of the current flowing through the photodiode 40 ₅ for monitoring.

If anti-resonance condition is satisfied, since the current value is the minimum flow in the photodiode 40 _5, as shown in FIG. 9 (b), until the current value flowing through the photodiode 40 ₅ by driving the heater 50 is minimized adjust. As a result, as shown in FIG. 9C, desired wavelength multiplexing / demultiplexing characteristics can be obtained. In other words, it is possible to the amount of current flowing through the photodiode 40 ₅ only controls so as to minimize, to obtain a flat transmission spectrum, it is possible to very easily waveform control.

  FIG. 10 is an explanatory diagram of the transmission spectrum characteristic and crosstalk improvement effect of one channel, FIG. 10A shows the transmission spectrum characteristic, and FIG. 10B shows the crosstalk. As shown in FIG. 10A, the phase shift generated in the manufacturing process is compensated by providing a monitor structure and a heater, so that the characteristics of the wavelength multiplexer / demultiplexer having the conventional structure shown in FIG. And low transmission loss and flat transmission spectral characteristics.

  In addition, the crosstalk XT shown in FIG. 10B is estimated to have a shape factor defined by the ratio of the bandwidth to -1 dB and -10 dB to ˜0.74, which is more than twice that of the conventional device. It is getting bigger. Also, the transmission spectrum flatness increases the bandwidth for obtaining XT below a certain value. In this case, the bandwidth at which XT in all channels is -10 dB or less is estimated to be 2.4 nm (75% of the wavelength interval) in the case of the element of the present invention, and is twice or more larger than that in the case of the conventional element. Yes.

Here, the following supplementary notes are attached to the embodiments of the present invention including Examples 1 to 3. (Supplementary note 1) The first delay Mach-Zehnder interferometer in which two optical waveguides having different optical path lengths are opposed to each other and optical couplers are formed on the input end side and the output end side, and the optical path length is relatively short. An add / drop ring resonator optically coupled to the arm waveguide and one of the optical couplers of the first delay Mach-Zehnder interferometer are cascade-connected, and the first delay Mach-Zehnder interferometer A second delay Mach-Zehnder interferometer and a third delay Mach-Zehnder interferometer having an optical path length difference of ½ of the optical path length difference, and the second delay Mach-Zehnder interferometer and the third delay Mach At least a first phase shifter provided on one side of the Zehnder interferometer, and the optical coupling rate on the add port side of the add / drop ring resonator is 10 to 30 times the optical coupling rate to the drop port side Is double Wavelength demultiplexer according to claim and.
(Supplementary note 2) The wavelength multiplexing / demultiplexing according to supplementary note 1, wherein the optical coupling factor on the add port side is 65% or more and the optical coupling factor on the drop port side is 6.5% or less vessel.
(Supplementary Note 3) An optical coupler on the downstream side of the cascade connection of the second delay Mach-Zehnder interferometer has an optical path length difference of ½ of the optical path length difference of the second delay Mach-Zehnder interferometer. A fourth delay Mach-Zehnder interferometer and a fifth delay Mach-Zehnder interferometer are cascade-connected, and a second one is connected to one of the fourth delay Mach-Zehnder interferometer and the fifth delay Mach-Zehnder interferometer. And an optical coupler on the downstream side of the cascade connection of the third delay Mach-Zehnder interferometer is half the optical path length difference of the third delay Mach-Zehnder interferometer. A sixth delay Mach-Zehnder interferometer and a seventh delay Mach-Zehnder interferometer having optical path length differences are cascade-connected, and the sixth delay Mach-Zehnder interferometer and the seventh delay map are connected. The wavelength according to appendix 1 or appendix 2, wherein the cascade connection structure in which the third phase shifter and the fourth phase shifter whose phase shift amounts are opposite to each other is provided in the Zehnder interferometer in order of multiple stages. Multiplexer / demultiplexer.
(Supplementary note 4) The wavelength multiplexer / demultiplexer according to any one of supplementary notes 1 to 3, wherein a monitor light receiver is provided at an output end of the drop port.
(Supplementary note 5) The wavelength multiplexer / demultiplexer according to supplementary note 4, wherein a heating member is provided so as to projectably cover at least a part of the add / drop ring resonator.
(Supplementary note 6) Any one of Supplementary notes 1 to 5, wherein a core layer of the arm waveguide and the add / drop ring resonator is made of silicon single crystal, and a clad layer covering the core layer is made of SiO _2. The wavelength multiplexer / demultiplexer according to claim 1.
(Supplementary note 7) The wavelength multiplexer / demultiplexer according to any one of supplementary notes 1 to 6 and the output terminal of each delay Mach-Zehnder interferometer constituting the cascade connection of the wavelength multiplexer / demultiplexer. An optical integrated circuit device comprising: a light receiver array formed by connecting devices.

10 ₁ to 10 ₃ DMZI
11 _{1 to} 11 ₃ , 12 _{1 to} 12 ₃ arm waveguides 13 _{1 to} 13 ₃ , 14 _{1 to} 14 ₃ optical coupler 15 ₃ phase shifter 16 ring resonator 17 waveguide 20 _{1 to} 20 ₇ DMZI
21 _{1 to} 21 ₇ , 22 _{1 to} 22 ₇ arm waveguide 23 ₁ to 23 ₇ , 24 _{1 to} 24 ₇ optical coupler 25 ₃ , 25 _{5 to} 25 ₇ phase shifter 26 ring resonator 27 waveguide 31 silicon substrate 32 SiO ₂ Film 33 Single crystal silicon layer 34 Resist pattern 35 Core layer 36 SiO ₂ film 37 Slab part 40 ₁ to 40 ₅ Photodiode 50 Heater 51 Ti pattern 52 SiO ₂ film 53 Al contact 80 ₁ to 80 ₇ DMZI
81 _{1-81 7, 82} 1-82 ₇ arm waveguides ₈₃ 1 _{to 83 7,} 84 1 to 84 ₇ optical coupler _{85 3,} 85 _5, 85 6, 85 ₇ the phase shifter 86 ring resonator 90 DMZI
91, 92 Arm waveguide 93, 94 Optical coupler 96 Ring resonator

Claims (5)

A first delay Mach-Zehnder interferometer in which two arm waveguides having different optical path lengths are opposed to each other and optical couplers are formed on the input end side and the output end side;
An optically coupled add / drop ring resonator of an arm waveguide having a relatively short optical path length;
The second delay Mach is cascade-connected via one optical coupler of the first delay Mach-Zehnder interferometer, and has an optical path length difference of ½ of the optical path length difference of the first delay Mach-Zehnder interferometer. A Zehnder interferometer and a third delay Mach-Zehnder interferometer;
A first phase shifter provided in one of the second delay Mach-Zehnder interferometer and the third delay Mach-Zehnder interferometer;
Comprising at least
2. A wavelength multiplexer / demultiplexer according to claim 1, wherein an optical coupling factor on the add port side of the add / drop ring resonator is 10 to 30 times an optical coupling factor to the drop port side.   2. The wavelength multiplexer / demultiplexer according to claim 1, wherein the optical coupling factor on the add port side is 65% or more and the optical coupling factor on the drop port side is 6.5% or less.   3. The wavelength multiplexer / demultiplexer according to claim 1, wherein a monitor light receiver is provided at an output end of the drop port.   The wavelength multiplexer / demultiplexer according to claim 3, wherein a heating member is provided so as to projectably cover at least a part of the add / drop type ring resonator. The wavelength multiplexer / demultiplexer according to any one of claims 1 to 3,
An optical integrated circuit device comprising: a light receiver array formed by connecting a light receiver to an output end of each delay Mach-Zehnder interferometer constituting the cascade connection of the wavelength multiplexer / demultiplexer .

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