Article Investigation on Chalcogenide Glass Additive Manufacturing for Shaping Mid-infrared Optical Components and Microstructured Optical Fibers
Julie Carcreff 1, François Cheviré 1 , Ronan Lebullenger 1, Antoine Gautier 1, Radwan Chahal 2, Jean Luc Adam 1, Laurent Calvez 1, Laurent Brilland 2, Elodie Galdo 1, David Le Coq 1 , Gilles Renversez 3 and Johann Troles 1,*
1 CNRS, University of Rennes, ISCR-UMR 6226, 35000 Rennes, France; [email protected] (J.C.); [email protected] (F.C.); [email protected] (R.L.); [email protected] (A.G.); [email protected] (J.L.A.); [email protected] (L.C.); [email protected] (E.G.); [email protected] (D.L.C.) 2 Selenoptics, 263 Avenue Gal Leclerc, 35042 Rennes, France; [email protected] (R.C.); [email protected] (L.B.) 3 CNRS, Centrale Marseille, Institut Fresnel, Aix-Marseille University, UMR 7249, 13013 Marseille, France; [email protected] * Correspondence: [email protected]; Tel.: +33-(0)2-23-23-67
Abstract: In this work, an original way of shaping chalcogenide optical components has been investigated. Thorough evaluation of the properties of chalcogenide glasses before and after 3D printing has been carried out in order to determine the impact of the 3D additive manufacturing Citation: Carcreff, J.; Cheviré, F.; process on the material. In order to evaluate the potential of such additive glass manufacturing, Lebullenger, R.; Gautier, A.; Chahal, several preliminary results obtained with various chalcogenide objects and components, such as R.; Adam, J.L.; Calvez, L.; Brilland, L.; cylinders, beads, drawing preforms and sensors, are described and discussed. This innovative 3D Galdo, E.; Le Coq, D.; et al. printing method opens the way for many applications involving chalcogenide fiber elaboration, but Investigation on Chalcogenide Glass Additive Manufacturing for Shaping also many other chalcogenide glass optical devices. Mid-infrared Optical Components and Microstructured Optical Fibers. Keywords: chalcogenide glasses; 3D printing; mid-infrared fibers; photonic crystal fibers Crystals 2021, 11, 228. https:// doi.org/10.3390/cryst11030228
Academic Editor: Shujun Zhang 1. Introduction In recent years, a growing interest has been developed for optical materials and fibers Received: 6 February 2021 for the mid-infrared (mid-IR) region, especially for chalcogenide glasses [1,2]. Such interest Accepted: 22 February 2021 originates from societal needs for health and environment for instance, and also from the Published: 25 February 2021 demand for military applications [3,4]. Indeed, the mid-IR spectral region contains the 3–5 µm and 8–12 µm atmospheric transparent windows, where both military and civilian Publisher’s Note: MDPI stays neutral thermal imaging can take place [5,6]. Compared to oxide-based glasses, vitreous materials with regard to jurisdictional claims in containing chalcogen elements, i.e., S, Se and Te, show large transparency windows in published maps and institutional affil- the infrared. Depending on their chemical composition, chalcogenide glasses can be iations. transparent from the visible up to 12–18 µm [7–9]. In this context, we have investigated an alternative approach based on a 3D printing process for fabricating mid-IR optical components such as preforms, optical fibers, sensors and beads. 3D printing, more formally known as additive manufacturing, was firstly a shap- Copyright: © 2021 by the authors. ing technique widely used for polymer for rapid prototyping processes but it is now Licensee MDPI, Basel, Switzerland. more and more commonly employed for mass production and mass customization, as This article is an open access article well [10–13]. Very quickly, this technology was extended to metals [14], ceramics [15] and distributed under the terms and even glasses [16–18]. The most common method for polymers is the fused filamentation conditions of the Creative Commons fabrication (FFF) method, also known as fused deposition modeling (FDM) [19,20]. It Attribution (CC BY) license (https:// involves the extrusion of a thermoplastic material through a heated die and accurate depo- creativecommons.org/licenses/by/ 4.0/). sition, layer by layer, until the desired three-dimensional object is obtained. It has been
Crystals 2021, 11, 228. https://doi.org/10.3390/cryst11030228 https://www.mdpi.com/journal/crystals Crystals 2021, 11, x FOR PEER REVIEW 2 of 14
layer by layer, until the desired three-dimensional object is obtained. It has been demon- strated that such filamentation techniques can be modified and applied to the 3D printing Crystals 2021, 11, 228of glasses with low glass transition temperature (Tg), also known as “soft glasses”, such 2 of 12 as chalcogenide glasses [21,22] and phosphate glasses as presented in reference [23]. In previous works, in reference [22], it has been shown that a microstructured optical fiber can be obtaineddemonstrated from a 3D thatprinted such chalcogenide filamentation techniques glass preform. can be The modified present and study applied is to a the 3D more completeprinting investigation of glasses of with the lowthermal glass transitionand optical temperature properties (Tg), of also the known chalcogenide as “soft glasses”, glasses after thesuch 3D asprinting chalcogenide process. glasses [21,22] and phosphate glasses as presented in reference [23]. For this work,In previous the 3D works,-printing in reference set-up is [22 based], it has on been a customized shown that desktop a microstructured RepRap-style optical fiber 3D printer runningcan be Marlin obtained firmware from a 3D [24] printed. This chalcogenide printer, typically glass preform. used with The present polymer study fila- is a more ments to producecomplete plastic investigation objects, was of upgrade the thermald to and reach optical a deposition properties oftemperature the chalcogenide of up glasses to 400 °C requiredafter for the soft 3D printingglasses process.and the feeding mechanism was customized to suitably For this work, the 3D-printing set-up is based on a customized desktop RepRap- handle brittle materials such as glasses. style 3D printer running Marlin firmware [24]. This printer, typically used with polymer Different filamentsphysical toand produce optical plastic properties objects, of was the upgraded printed toglasses reach asuch deposition as density, temperature ther- of up mal expansionto coefficient, 400 ◦C required refractive for soft indices, glasses and and transmission the feeding mechanism have been was investigated customized and to suitably compared to thehandle properties brittle materialsof classical such melt as- glasses.quenched glasses. By using this additive man- ufacturing method,Different chalcogenide physical cylinders, and optical pellets, properties beads of the, as printedwell as glasses microstructured such as density, per- thermal forms with complexexpansion designs coefficient, can be refractive fabricated indices, in a single and transmission step with a have high been degree investigated of re- and peatability andcompared an accuracy to the of propertiesthe geometry. of classical This original melt-quenched 3D printing glasses. method By using opens this the additive way for numerousmanufacturing applications method,, involving chalcogenide chalcogenide cylinders, pellets, fiber man beads,ufacturing as well as, microstructuredbut also performs with complex designs can be fabricated in a single step with a high degree of many other chalcogenide glasses optical devices. repeatability and an accuracy of the geometry. This original 3D printing method opens the way for numerous applications, involving chalcogenide fiber manufacturing, but also 2. Materials andmany Methods other chalcogenide glasses optical devices. 2.1. Thermal and Physical Optical Properties of the Chosen Glass : Te20As30Se50 2. Materials and Methods The selected glass for printing shall present thermal properties compatible with man- 2.1. Thermal and Physical Optical Properties of the Chosen Glass: Te20As30Se50 ufacture by fused filamentation fabrication. To begin, the use of a commercial extrusion The selected glass for printing shall present thermal properties compatible with head usually utilizedmanufacture for conventional by fused filamentation thermoplastics fabrication. such To begin, as polylactic the use of acid a commercial (PLA) re- extrusion quires that the headselected usually glass utilized shows for a conventional low glass transition thermoplastics temperature such as polylactic (Tg). In acidaddition, (PLA) it requires would be preferablethat the that selected the glass glass showsis stable a low with glass respect transition to crystallization. temperature (T gIn). Inthis addition, context, it would the Te20As30Se50be (TAS) preferable chalcogenide that the glass glass is that stable exhibits with respect a Tg slightly to crystallization. below 140 In°C thisappears context, the ◦ to be a good candidateTe20As30Se [25]50 (TAS). Figure chalcogenide 1a shows glassthe differential that exhibits scanning a Tg slightly calorimetry below 140 (DSC)C appears curve of the TASto beglass a good measured candidate with [25 a]. DSC Figure Q201a showsfrom TA the differentialinstrument scanning with a heating calorimetry rate (DSC) curve of the TAS glass measured with a DSC Q20 from TA instrument with a heating rate of 10 °C/min. The glass exhibits a Tg close to 137 °C and no sign of crystallization are ob- of 10 ◦C/min. The glass exhibits a T close to 137 ◦C and no sign of crystallization are served up to 300 °C, which confirms that the glassg could be compatible with the FFF 3D observed up to 300 ◦C, which confirms that the glass could be compatible with the FFF 3D printing process.printing process.
Figure 1. Thermal properties of the Te20AS30Se50 (TAS) chalcogenide glasses: (a) differential scanning calorimetry measure- ment, (b) viscosity versus temperature curve. Figure 1. Thermal properties of the Te20AS30Se50 (TAS) chalcogenide glasses: (a) differential scan- ning calorimetry measurement,The implementation (b) viscosity of versus a filamentation temperature process curve with. this glass also requires a better knowledge of its viscosity as a function of temperature. For this purpose, a TAS pellet was
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prepared in order to measure the viscosity. Both sides of the printed disk (15 mm diameter, 4 mm height) were polished to ensure that they were parallel. The viscosity of the glass was measured above the glass transition temperature between 140 and 230 °C by using a Rheotronic®parallel plate viscometer (Theta industries). This experimental set-up did not permit one to measure viscosities lower than 104 Pa.s. This value is reached when the temperature of the glass is equal to 230 ◦C. However, considering that experimental data follow the VFT (Vogel–Fulcher–Tammann) law, the viscosity value can be estimated up to 300 ◦C using a fitting procedure from Equations (1) and (2) [26], as shown in Figure1b. This enables one to estimate the flow rate and, therefore to optimize the process.
A log10 η(T) = log10η∞ + (1) T − T0
This equation can also be written as follows: