Single Step Optical Fabrication of a DFB Laser Device in Fluorescent Azobenzene-Containing Materials
Single Step Optical Fabrication of a DFB Laser Device in Fluorescent Azobenzene-Containing Materials
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DOI：
10.1002/adma.201200698
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发表时间：
2012-07-03
影响因子：
29.4
通讯作者：
Schrader, Sigurd
中科院分区：
文献类型：
--
作者：
Goldenberg, Leonid M.;Lisinetskii, Victor;Schrader, Sigurd
图案化荧光薄膜在光子学、光电子学、显示技术等领域的不同应用中引起了极大的兴趣[1]可行的应用包括显示器、光学存储设备、分子开关、传感器和安全功能（有关最近的评论，请参阅[2]）。进行图案化的一种可能性是干涉曝光（例如全息刻字），可以通过荧光纳米颗粒的扩散在体全息材料中实现[3]，或者通过引入荧光团[4]在含偶氮苯的表面浮雕全息材料中实现。最后的材料在过去 15 年里已用于表面浮雕光栅 (SRG) 制造。[5]然而，在这些系统中制造荧光光栅仍然不是微不足道的，因为偶氮苯本身和其他荧光团的荧光都被猝灭到这样的程度，例如，偶氮苯衍生物 Dabcyl 是一种常用的荧光猝灭剂。 [6]一些研究人员报告称，某些偶氮苯衍生物具有强荧光，通过引入吸收波长高于偶氮苯吸收的荧光团，基本上抑制了猝灭。 [7]在被偶氮苯部分取代的聚亚苯基亚乙烯基和聚噻吩薄膜中也观察到荧光。 [8]因此，含偶氮苯材料中的荧光 SRG 最近才得到证实。[4]其中一些是采用新型材料生产的，与传统的含偶氮苯的侧链聚合物不同。 [4b]新材料可以形容为易于制备，暂可分为超分子聚合物和无定形低分子量材料（分子玻璃，综述见[5, 9]）。此外，新材料通常在效率或附加功能方面优于传统聚合物。[10-12]从某种意义上说，它们可以被描述为先进和/或高级功能材料。与其他人一起 [11, 13]，我们也为这些先进材料的开发做出了巨大贡献。[10, 12] 这使得聚电解质材料 PAZO 具有较高的热稳定性，[10a] 超分子离子材料的调制深度达到创纪录的 1.8 µm [10b]，并且在通过环氧环点击反应获得的低聚物中创纪录的刻录率。[10c] 在薄层材料中也观察到了高刻录率。 显示光触发机制的层液晶材料。[10d] 现在，我们使用这种广泛的材料调色板来应对创建含偶氮苯荧光全息材料的挑战。此类材料可能对产生荧光全息图的安全功能感兴趣，但该方法的另一个有趣应用可能是一种仅使用单个全光学步骤创建分布式反馈（DFB）激光器的新方法。据我们所知，迄今为止，在含偶氮苯材料中创建激光DFB结构的尝试都失败了[14, 15]，甚至有人指出[15b]，为了实现这一目标，必须将具有DFB结构的偶氮苯层与活性光产生层分离。这是由于全息曝光期间荧光团被光漂白的额外问题。使用全息刻录 DFB 结构的两层激光器件（分离的偶氮苯和活性层）已经实现。[14-18]含偶氮苯材料中的 SRG 也被用作在其他材料中复制 DFB 结构的母版。[19]最近，基于紫外光聚合物烧蚀的干涉曝光已被用于直接制造聚合物 DFB 激光器。 [20]这种单步方法的优点是……
Patterning fluorescent films is of great interest for different applications in photonics, optoelectronics, display technique, etc.[1] Feasible applications are displays, optical memory devices, molecular switches, sensors, and security features (see [2] for recent review). One of the possibilities to perform the patterning is interference exposure (eg, holographic inscription), that can be realized in volume holographic materials via a diffusion of fluorescent nanoparticles [3] or in surface relief azobenzene-containing holographic materials via an introduction of fluorophores.[4] The last materials are already used for surface relief grating (SRG) fabrication for the last 15 years.[5] However, the fabrication of fluorescent gratings in these systems is still not trivial, because the fluorescence of both azobenzene itself and additional fluorophores is quenched to such an extent that, for example, an azobenzene derivative Dabcyl is a commonly used fluorescence quencher.[6] Some researchers reported strong fluorescence in certain azobenzene derivatives, where the quenching has essentially been suppressed by introducing a fluorophore absorbing at wavelengths higher than an absorption of the azobenzene.[7] Fluorescence was also observed in films of polyphenylene vinylene and polythiophene substituted with azobenzene moieties.[8] Therefore, fluorescent SRGs in azobenzene-containing materials are only recently demonstrated.[4] Some of them were produced using new types of materials, which differ from the traditional azobenzene-containing sidechain polymers.[4b] New materials can be described as easy made and could be tentatively divided into supramolecular polymers and amorphous low-molecular weight materials (molecular glasses, see [5, 9] for review). In addition, new materials are often superior to traditional polymers either in efficiency or additional functionality.[10–12] In a sense they can be described as advanced and/or advanced functional materials. Along with others [11, 13] we have also heavily contributed in development of these advanced materials.[10, 12] That resulted in a high thermal stability in polyelectrolyte material PAZO,[10a] a record modulation depth of 1.8 µ m [10b] in supramolecular ionic materials, and a record inscription rate in oligomers obtained via epoxy ring click reaction.[10c] A high inscription rate was also observed in thin layer LC materials showing a photo-triggered mechanism.[10d] Now using this wide palette of materials we have attacked a challenge of creating fluorescent holographic azobenzene-containing materials. Such materials might be of interest for security features leading to the fluorescent holograms, but an additional interesting application of the approach could be a new methodology to create distributed feedback (DFB) lasers using just a single all-optical step. To the best of our knowledge the attempts to create lasing DFB structures in azobenzene-containing materials failed so far [14, 15] and even it was stated [15b] that to achieve this goal one has to separate the azobenzene layer with the DFB structure from the active light generating layer. This is due to the additional problem of fluorophore bleaching by light during holographic exposure. Two-layers laser devices (separated azobenzene and active layers) using holographically inscribed DFB structures have been realized.[14–18] SRGs in azobenzene-containing material were also used as a master for the replication of DFB structures in other materials.[19] Very recently interference exposure based on a polymer ablation by UV-light has been used for direct fabrication of a polymer DFB laser.[20] Advantages of such single step approach are the …