WO2014117674A1 - 基于聚焦离子束刻蚀光波导的方法 - Google Patents

基于聚焦离子束刻蚀光波导的方法 Download PDF

Info

Publication number
WO2014117674A1
WO2014117674A1 PCT/CN2014/071254 CN2014071254W WO2014117674A1 WO 2014117674 A1 WO2014117674 A1 WO 2014117674A1 CN 2014071254 W CN2014071254 W CN 2014071254W WO 2014117674 A1 WO2014117674 A1 WO 2014117674A1
Authority
WO
WIPO (PCT)
Prior art keywords
etching
ion beam
nano
focused ion
optical waveguide
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.)
Ceased
Application number
PCT/CN2014/071254
Other languages
English (en)
French (fr)
Inventor
姜潇潇
司光远
谷琼婵
王凤文
吕江涛
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Northeastern University China
Original Assignee
Northeastern University China
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by Northeastern University China filed Critical Northeastern University China
Publication of WO2014117674A1 publication Critical patent/WO2014117674A1/zh
Anticipated expiration legal-status Critical
Ceased legal-status Critical Current

Links

Classifications

    • G—PHYSICS
    • G02—OPTICS
    • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B6/00—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings
    • G02B6/10—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings of the optical waveguide type
    • G02B6/12—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings of the optical waveguide type of the integrated circuit kind
    • G02B6/13—Integrated optical circuits characterised by the manufacturing method
    • G02B6/136—Integrated optical circuits characterised by the manufacturing method by etching

Definitions

  • the present invention relates to the field of optical device technologies, and in particular, to a method for etching optical waveguides based on focused ion beam etching.
  • Optical waveguides are widely used in the preparation of various types of optical devices.
  • the experimental preparation of optical waveguides mainly includes wet etching and dry etching.
  • wet etching is to etch a material for preparing an optical waveguide by using a corrosive acid solution and finally form a waveguide.
  • the preparation principle is as shown in Fig. 1. By masking with a mask, the acid solution is only etched on the exposed portion of the sample, and the blocked portion is not etched (Note: the substance used as a mask) Need to resist acid corrosion). It is through this selective etching that the desired optical waveguide structure is finally formed.
  • wet etching is affected by many factors due to the reaction of the material to be etched and the acid solution, making the etching process difficult to control.
  • the rate of reaction is closely related to the solubility, temperature, and pressure of the solution.
  • This non-uniform waveguide shape causes excessive losses in the transmission of light, reduces the efficiency of the device, and limits the range of use of the device.
  • the most common method is plasma etching. Compared to wet etching, this method has a low etching rate, but it can achieve good control of the etching process. In addition, the degree of verticality of the side wall of the optical waveguide is improved to some extent. However, it is still impossible to obtain a large etching depth and a high duty ratio using a plasma etching method (the aspect ratio is defined as the etching depth/etching width) because although the ions can be The surface of the sample is bombarded at high speed by the action of an accelerating electric field, but the incident direction of the ion bombarding the sample is not all completely perpendicular to the surface of the sample. As shown in the schematic diagram of Fig.
  • the present invention provides an optical waveguide manufacturing method based on focused ion beam etching to obtain an optical waveguide structure having a deep etching ultra-high duty ratio and almost completely vertical sidewalls.
  • the present invention provides a method of etching an optical waveguide based on a focused ion beam, the method comprising:
  • the nano ring array structure is saved in a focused ion beam etching system
  • the nano-ring array structure is called from a focused ion beam system, and the focused ion beam vertically bombards the surface of the sample for etching to complete the preparation.
  • the minimum width of the etched width of the optical waveguide is 20 nm.
  • the invention adopts a nano ring structure closely adjacent to each other for focused ion beam etching, and the ultra-high duty ratio optical waveguide has an almost vertical sidewall structure, and the waveguide and the optical device composed of the structure have ultra low transmission loss.
  • the performance of the device can be greatly improved.
  • the corresponding application range is also greatly expanded, and the resulting device not only has superior performance and stability, but also accurately reproduces the transmitted and saved optical signals.
  • Figure 1 is a schematic view of the working principle of wet etching
  • FIG. 2 is a schematic view showing the working principle of the plasma etching method
  • Figure 3 is a schematic diagram of the working principle of the focused ion beam etching method
  • Figure 4 is a compact annular array structure
  • Figure 5 is a flow chart showing the steps of the preparation method of the present invention
  • Figure 6 is a cross-sectional scanning electron microscope image of the ultra-high duty ratio optical waveguide structure
  • Figure 7 is a comparison diagram of effects using a conventional wet/plasma etching method and a focused ion beam etching method using a ring structure in the present invention
  • Figure 8 is a diagram of a complex diamond shaped optical waveguide prepared using the method proposed by the present invention.
  • the invention uses a focused ion beam (FIB) etching method, and its working principle is shown in FIG.
  • the gallium ions accelerated by the electric field are focused onto the surface of the sample through a focusing mirror, and a certain area of the surface of the sample is removed by a sputtering reaction to form a different structure.
  • This technique eliminates the need for a mask and is a maskless direct etch method. Moreover, this method is applicable to almost all substances (the etch rate will vary for different substances).
  • the method of etching an optical waveguide based on a focused ion beam includes:
  • the ion beam is easier to focus on the ring structure, and most of the ion beam energy can be confined in the ring region, and the ring structures are in close contact with each other, so that the focused ion beam is located in the ring region during the etching process.
  • the energy can overlap, thereby multiplying the penetration of the ion beam.
  • the surface of the sample is bombarded at a high speed in the vertical direction, so that the etching depth can be greatly increased, thereby making the ultra-high duty ratio junction
  • the composition is possible.
  • the width of the etch is fixed to a minimum of 20 nm, but due to the error of the equipment system, the etching is not necessarily accurate. On this basis, the etching depth is increased as much as possible, and the waveguide structure with ultra-high duty ratio is obtained to the maximum extent.
  • the top end of the waveguide structure exhibits relatively serious damage caused by long-time etching.
  • the ion beam damages the surface of the structure, and on the other hand, the material to be etched is redeposited to be damaged.
  • the waveguide structure becomes very vertical and uniform from about 2 ⁇ m below the surface of the sample. For most areas of the waveguide structure (the portion below 2 ⁇ ), not only the etching width is extremely small. (20 nm), and the sidewalls are vertical and uniform, which will reduce d and the loss of light during waveguide transmission, which greatly improves the performance of the waveguide.
  • This annular array structure can effectively reduce the redeposition effect during the focused ion beam etching process, thereby greatly improving the sidewall structure of the device and increasing the etching depth.
  • Another benefit of using this structure for etching is high controllability.
  • the structure of the waveguide can be effectively controlled by adjusting the inner and outer diameters of the ring.
  • This structure is previously drawn and stored in a computer focused on the ion beam etching system, and the desired corresponding structure can be directly etched as needed.
  • Figure 7 is a comparison of effects using a conventional wet/plasma etching method and a focused ion beam etching method using a ring structure.
  • Another significant advantage of using this method is the ability to fabricate complex diamond-shaped optical waveguides that intersect each other, as shown in Figure 8.
  • This structure can be widely used to prepare Fabry-Perot interferometers.
  • Optical signals of different modes propagate and interact in different optical paths.
  • optical outputs with various application backgrounds can be effectively formed.
  • the optical signals in the different optical channels interfere with each other due to the phase difference, and further form an interferometer.

Landscapes

  • Physics & Mathematics (AREA)
  • Engineering & Computer Science (AREA)
  • Microelectronics & Electronic Packaging (AREA)
  • General Physics & Mathematics (AREA)
  • Optics & Photonics (AREA)
  • Optical Integrated Circuits (AREA)

Abstract

本发明提供一种基于聚焦离子束刻蚀光波导的方法，该方法包括：S1、设计一种纳米圆环阵列结构，所述纳米圆环阵列结构中纳米圆环互相紧贴，光波导的刻蚀宽度值为两倍的圆环宽度；S2、将所述纳米圆环阵列结构保存到聚焦离子束刻蚀系统中；S3、从聚焦离子束系统中调用所述纳米圆环阵列结构，聚焦离子束轰击样品表面进行刻蚀，完成制备。通过本发明制造的光波导结构具有超高占空比，几乎垂直的侧壁。

Description

说明书 基于聚焦离子束刻蚀光波导的方法 技术领域
本发明涉及光学器件技术领域，具体涉及一种基于聚焦离子束刻蚀光波 导的方法。
背景技术
光波导广泛应用于制备各类光学器件中， 光波导的实验制备主要有湿法 刻蚀和干法刻蚀两种方法。其中湿法刻蚀是通过使用具有腐蚀性的酸溶液对 用于制备光波导的材料进行刻蚀并最终形成波导。 其制备原理如图 1所示， 通过使用掩膜遮挡， 使得酸溶液只对暴露在外的样品部分进行刻蚀， 被遮挡 住的部分则不会被刻蚀（注： 当作掩膜使用的物质需抗酸的腐蚀）。 正是通 过这种选择性刻蚀， 最终形成所需要的光波导结构。 湿法刻蚀由于需被刻蚀 的材料和酸溶液的反应受到诸多因素的影响， 使得刻蚀过程不易被控制。 比 如， 反应的速率和溶液的溶度、 温度、 以及压强关系密切。 在刻蚀过程中， 必须确保各种影响反应速率的因素稳定、 无波动， 否则会造成刻蚀的结果不 均一。 这种不均一的波导形状会造成光在其中传输时产生过大的损耗， 降低 器件的工作效率， 制约器件的使用范围。
对于干法刻蚀而言， 最常用的方法为等离子刻蚀（plasma etching )。 相 较于湿法刻蚀， 这种方法刻蚀速率偏低， 但是却能对刻蚀过程达到艮好的控 制。 此外， 对于光波导的侧壁， 其垂直程度会得到一定程度的改善。 但是， 使用等离子刻蚀法依然无法得到很大的刻蚀深度和很高的占空比（占空比英 文为 aspect ratio, 定义为刻蚀深度 /刻蚀宽度），这是因为虽然离子可以在加 速电场的作用下以高速轰击样品表面，但是离子轰击样品时的入射方向并非 全部完全垂直于样品表面。 如图 2中的示意图所示， 也就是说， 大部分离子 是倾斜一定的角度轰击样品表面并移除物质从而形成波导的。可见不论是使 用湿法刻蚀还是使用等离子刻蚀， 都有一个不可避免的问题， 那就是所制备 的波导的侧壁参差不齐且不垂直，都 4艮难得到大尺寸的刻蚀深度和具有超高 占空比的结构。
发明内容
(一）所要解决的技术问题
为解决上述技术问题， 本发明提供一种基于聚焦离子束刻蚀的光波导制 备方法， 得到具有深度刻蚀的超高占空比和几乎完全垂直侧壁的光波导结 构。
(二）技术方案
本发明提供一种基于聚焦离子束刻蚀光波导的方法， 该方法包括：
51、 设计一种纳米圓环阵列结构， 所述纳米圓环阵列结构中纳米圓环互相紧 贴， 光波导的刻蚀宽度值为两倍的圓环宽度；
52、 将所述纳米圓环阵列结构保存到聚焦离子束刻蚀系统中；
53、 从聚焦离子束系统中调用所述纳米圓环阵列结构， 聚焦离子束垂直轰击 样品表面进行刻蚀， 完成制备。
其中， 所述光波导的刻蚀宽度最小值为 20 nm。
(三 )有益效果
本发明采用互相紧贴的纳米环结构进行聚焦离子束刻蚀，超高占空比光 波导具有几乎垂直的侧壁结构， 由这种结构所组成的波导及光学器件具有超 低的传输损耗， 可以使得器件的工作性能得到大幅改善。 相应的应用范围也 会大幅度扩展， 得到的器件不但性能优越、 稳定， 而且能准确地再现所传输 和保存的光信号。
附图说明
图 1为湿法刻蚀的工作原理示意图；
图 2为等离子刻蚀法的工作原理示意图；
图 3为聚焦离子束刻蚀法工作原理示意图；
图 4为紧凑型圓环阵列结构； 图 5为本发明制备方法步骤流程图；
图 6为超高占空比光波导结构的截面扫描电子显微镜图；
图 7为使用传统的湿法 /等离子刻蚀法和本发明中使用圓环结构的聚焦 离子束刻蚀法的效果对比图；
图 8为运用本发明提出的方法制备的复杂菱形光波导。
具体实施方式
下面结合附图和具体实施例对本发明做进一步详细说明。
本发明使用聚焦离子束（focused ion beam, 筒记为 FIB )刻蚀方法， 其工作原理示意图如图 3所示。 经过电场加速后的镓离子通过一个聚束镜被 聚焦到样品的表面， 通过溅射反应将样品表面一定区域的物质移除掉， 进而 形成不同的结构。 这种技术无需使用掩膜， 是一种无掩膜的直接刻蚀方法。 而且，这种方法几乎适用于所有物质（对于不同物质，刻蚀速率会有所不同） 具体的， 如图 4所示， 基于聚焦离子束刻蚀光波导的方法包括：
Sl、 设计一种纳米圓环阵列结构， 所述纳米圓环阵列结构中纳米圓环互 相紧贴， 光波导的刻蚀宽度值为两倍的圓环宽度；
S 2、 将所述纳米圓环阵列结构保存到聚焦离子束刻蚀系统中；
S 3、 从聚焦离子束系统中调用所述纳米圓环阵列结构， 聚焦离子束垂直 轰击样品表面进行刻蚀， 完成制备。
在刻蚀过程中， 为了得到高的占空比（刻蚀深度 /刻蚀宽度）， 必须尽 量增大刻蚀深度并减小刻蚀的宽度。 为了在最大限度内得到超高占空比的光 波导结构， 本发明特使用了一种纳米圓环阵列结构进行刻蚀， 纳米圓环阵列 结构如图 5所示，每行每列中的圓环互相紧贴，其中 r2和 ^分别表示聚焦离 子束刻蚀过程中圓环结构的外半径和内半径， 光波导的刻蚀宽度为 g=2 x (Γ2- )。 离子束对于圓环结构更容易聚焦， 大部分的离子束能量可以被 4艮好 地限制在圓环区域中， 圓环结构互相紧贴， 使得聚焦离子束在刻蚀过程中位 于圓环区域的能量能够重叠， 从而使得离子束的穿透力倍增。 在垂直方向上 以高速轰击样品表面， 使得刻蚀深度可以大幅增加， 进而使得超高占空比结 构成为可能。
在刻蚀过程中， 把刻蚀的宽度固定在最小值为 20 nm, 但由于设备系统 的误差， 刻蚀后并不一定是准确的 20 謹。 在此基础上尽可能增大刻蚀深度， 进而在最大限度内得到超高占空比的波导结构。 图 6中所示结构， 宽度为 20 nm, 深度约为 15 μ ηι ( Ι μ ηι =1000 nm=l χ 10 " 6m ) 的波导结构， 其对应的占 空比为 750。 值得注意的是， 波导结构的顶端会呈现出相对较严重的损伤， 这是由长时间的刻蚀造成的。 一方面是离子束对结构表面的损伤， 另一方面 是被刻蚀的材料再沉积到受到损伤的结构表面。 但是， 从样品表面约 2 μ ηι 以下， 波导结构就变得非常垂直且均一了。 对于波导结构的大部分区域而言 ( 2 μ ηι以下的部分）， 不但刻蚀宽度极小 （20 nm ), 而且侧壁垂直、 均一， 这些都会减 d、光在波导传输过程中的损耗， 使得波导的性能大幅度提高。
使用这种方法不但可以得到具有超高占空比的光波导， 而且所制备得到 的波导结构的侧壁几乎完全垂直， 正如图 6中所示。 这种几乎垂直的侧壁会 大大降低光在其中传输时的损耗， 且由于波导宽度 4艮小， 光波的大部分能量 可以很好地限制在波导区域内。
这种圓环阵列结构可以有效降低在聚焦离子束刻蚀过程中的再沉积效 应， 从而大幅度改善器件的侧壁结构和增大刻蚀深度。 使用这种结构进行刻 蚀的另一个好处是高度可控性。 波导的结构可以通过调节圓环的内、 外径进 行有效控制。 这种结构事先被画好并保存到聚焦离子束刻蚀系统的电脑中， 需要的时候可直接调用所需的相应结构进行刻蚀。 图 7为使用传统的湿法 / 等离子刻蚀法和使用圓环结构的聚焦离子束刻蚀法的效果对比图。
运用此方法的另一个显著的优点是可以制备出互相交叉的复杂菱形光 波导， 如图 8所示。 这种结构可以被广泛用于制备法布里-珀罗干涉仪。 不 同模式的光学信号在不同的光路中传播并相互作用，通过精确控制光波的相 位和能量大小， 可以有效形成具有各种不同应用背景的光学输出。 不同光通 道中的光信号之间由于相位差而互相干涉， 并进一步形成干涉仪。
以上所述仅是本发明的优选实施方式， 应当指出， 对于本技术领域的普 通技术人员来说， 在不脱离本发明技术原理的前提下， 还可以做出若干改进 和替换， 这些改进和替换也应视为本发明的保护范围。

Claims

权利要求
1、 一种基于聚焦离子束刻蚀光波导的方法， 其特征在于， 该方法包括:
51、 设计一种纳米圓环阵列结构， 所述纳米圓环阵列结构中纳米圓环互 相紧贴， 光波导的刻蚀宽度值为两倍的圓环宽度；
52、 将所述纳米圓环阵列结构保存到聚焦离子束刻蚀系统中；
53、 从聚焦离子束系统中调用所述纳米圓环阵列结构， 聚焦离子束轰击 样品表面进行刻蚀， 完成制备。
2、 如权利要求 1所述方法， 其特征在于， 所述光波导的刻蚀宽度最小 值为 20
PCT/CN2014/071254 2013-01-31 2014-01-23 基于聚焦离子束刻蚀光波导的方法 Ceased WO2014117674A1 (zh)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
CN201310038365.9 2013-01-31
CN201310038365.9A CN103064147B (zh) 2013-01-31 2013-01-31 基于聚焦离子束刻蚀光波导的方法

Publications (1)

Publication Number Publication Date
WO2014117674A1 true WO2014117674A1 (zh) 2014-08-07

Family

ID=48106844

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/CN2014/071254 Ceased WO2014117674A1 (zh) 2013-01-31 2014-01-23 基于聚焦离子束刻蚀光波导的方法

Country Status (2)

Country Link
CN (1) CN103064147B (zh)
WO (1) WO2014117674A1 (zh)

Families Citing this family (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN103064147B (zh) * 2013-01-31 2015-12-09 东北大学秦皇岛分校 基于聚焦离子束刻蚀光波导的方法
CN104992670B (zh) * 2015-07-07 2018-04-06 西安诺瓦电子科技有限公司 拼接亮暗线补偿方法
CN106353852B (zh) * 2016-11-18 2019-08-02 安徽蓝海之光科技有限公司 一种低成本的长周期光纤光栅制作方法

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN101008681A (zh) * 2007-01-26 2007-08-01 北京大学 一种制备二维光子晶体或光子准晶的方法
CN102981199A (zh) * 2012-11-13 2013-03-20 东北大学秦皇岛分校 表面等离子体纳米环滤光器
CN103064147A (zh) * 2013-01-31 2013-04-24 东北大学秦皇岛分校 基于聚焦离子束刻蚀光波导的方法

Family Cites Families (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2005111679A1 (en) * 2004-05-08 2005-11-24 The Board Of Trustees Of The Leland Stanford Junior University Photonic-bandgap fiber with hollow ring
CN102023386A (zh) * 2009-09-16 2011-04-20 中国科学院微电子研究所 阵列全环光子筛匀光器及其制作方法

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN101008681A (zh) * 2007-01-26 2007-08-01 北京大学 一种制备二维光子晶体或光子准晶的方法
CN102981199A (zh) * 2012-11-13 2013-03-20 东北大学秦皇岛分校 表面等离子体纳米环滤光器
CN103064147A (zh) * 2013-01-31 2013-04-24 东北大学秦皇岛分校 基于聚焦离子束刻蚀光波导的方法

Non-Patent Citations (4)

* Cited by examiner, † Cited by third party
Title
BAIDA, F.I. ET AL.: "Light transmission by subwavelength annular aperture arrays in metallic films.", OPTICS COMMUNICATIONS, vol. 209, no. 1-3, 1 August 2002 (2002-08-01), pages 17 - 22 *
LV , JIANGTAO ET AL.: "Nanoring color filters based on fabry-Pérot cavities", ACTA PHYSICA SINICA, vol. 62, no. 5, 28 March 2013 (2013-03-28), pages 057804-1 - 057804-5 *
MA, XIANGGUO ET AL.: "Application of FIB in micro/nano processing technology", VACUUM, vol. 44, no. 6, 30 November 2007 (2007-11-30), pages 74 - 78 *
POUJET, Y. ET AL.: "Super-transmission of light through subwavelength annular aperture arrays in metallic films: Spectral analysis and near-field optical images in the visible range.", PHOTONICS AND NANOSTRUCTURES-FUNDAMENTALS AND APPLICATIONS., vol. 4, no. 1, 6 January 2006 (2006-01-06), pages 47 - 53 *

Also Published As

Publication number Publication date
CN103064147B (zh) 2015-12-09
CN103064147A (zh) 2013-04-24

Similar Documents

Publication Publication Date Title
TWI710016B (zh) 繞射光柵之製造
Prather et al. Photonic crystals
CN112034550B (zh) 基于悬空波导结构的氮化硅相控阵芯片
CN109541745A (zh) 一种耦合区改进型的微环谐振器及其制作方法
JP2014063866A (ja) シリコン基板の加工方法及び荷電粒子線レンズの製造方法
CN108646329A (zh) X射线自支撑闪耀透射光栅的制备方法
CN104386645A (zh) 自掩膜制备随机亚波长宽带减反射微结构的方法
WO2014117674A1 (zh) 基于聚焦离子束刻蚀光波导的方法
US20260055023A1 (en) Method of surface structuring a substrate body and substrate body
WO2017145706A1 (ja) 薄膜部材の湾曲加工方法
TW201135829A (en) A novel fabrication method for producing undercut-etching microstructure
CN115417372A (zh) 一种石英三维结构加工方法
Cho et al. Single-and multi-directional slanted plasma etching of silicon under practical plasma processing conditions
CN110286432B (zh) X射线金透射光栅的制备方法
US20210026150A1 (en) Birefringent waveplate and method for forming a waveplate having a birefringent metasurface
CN103018806B (zh) 一种亚波长极紫外金属透射光栅及其制作方法
CN112071740B (zh) 一种用皮秒激光照射制备碳化硅结构的方法
JP2007133153A (ja) マイクロレンズ用型の製造方法
CN106556891A (zh) 一种表面突起的波导三维模斑转换器及其制作方法
CN112612078A (zh) 一种基于goi或soi上的高效耦合波导及其制备方法
CN106981543B (zh) 采用铝硅共晶薄膜辅助干法刻蚀制备黑硅层的方法
Tang et al. Comparison of optimised conditions for inductively coupled plasma‐reactive ion etching of quartz substrates and its optical applications
CN106099637A (zh) 基于纳米压印光栅的两步干法刻蚀方法及外延片和激光器
CN102096149B (zh) 一种硅基长波红外光波导及其制备方法
Yavuzcetin et al. Photonic crystal fabrication in lithium niobate via pattern transfer through wet and dry etched chromium mask

Legal Events

Date Code Title Description
121 Ep: the epo has been informed by wipo that ep was designated in this application

Ref document number: 14746283

Country of ref document: EP

Kind code of ref document: A1

NENP Non-entry into the national phase

Ref country code: DE

32PN Ep: public notification in the ep bulletin as address of the adressee cannot be established

Free format text: NOTING OF LOSS OF RIGHTS PURSUANT TO RULE 112(1) EPC (EPO FORM 1205A DATED 23/11/2015)

122 Ep: pct application non-entry in european phase

Ref document number: 14746283

Country of ref document: EP

Kind code of ref document: A1