Shape-memory polymers as flexible resonator substrates for continuously tunable organic DFB lasers

Abstract

Abstract:We introduce shape-memory polymers (SMP) as substrate material for active optical devices. As an exemplary application we build a tunable organic semiconductor distributed feedback (DFB) laser. Hence, we transfer a second order Bragg grating with a period of 400 nm into SMP foils by hot embossing. The composite organic gain medium Alq 3 :DCM evaporated on the SMP substrate serves as laser active material. Mechanical stretching of the substrate increases the grating period temporarily and triggering the shape-memory effect afterwards reduces the period on demand. In this way, we can adjust the grating period to achieve a broad continuously tuning of the laser emission wavelength by 30 nm.

Tuning of Structural Colors Like a Chameleon Enabled by Shape‐Memory Polymers

“…This ability arises from the special molecular structure of those polymers in combination with a specific programming cycle . Although SMPs have been introduced to the field of optics only recently, their applicability has been already proven . The SMP utilized in this study is a thermoplastic, thermally‐activated poly(ether urethane) block‐copolymer (TecoflexEG‐72D, Lubrizol, USA).…”

“…Since it is completely amorphous it is transparent in the visible range and it is very robust and docile in terms of its shape memory features. Its recovery time can be controlled via the recovery temperature and the recovery process can be even stopped and restarted on purpose . We produced the polymer opals presented here by blending different percentages of this SMP with monodisperse core‐shell polymer particles and ordering the particles using shear (as developed over the last decade).…”

“…The color of the stretched middle part of the strip shifted from green back to red as the sample recovers its original length. This proof of concept experiment demonstrates the continuous color change which can be stopped at any intermediate stage by cooling the sample …”

“…[20][21][22][23][24][25] Although SMPs have been introduced to the field of optics only recently, their applicability has been already proven. [26][27][28][29][30][31][32] The SMP utilized in this study is a thermoplastic, thermally-activated poly(ether urethane) block-copolymer (TecoflexEG-72D, Lubrizol, USA). Since it is completely amorphous it is transparent in the visible range and it is very robust and docile in terms of its shape memory features.…”

Thin-film organic semiconductor devices: from flexibility to ultraflexibility

“…The flexible substrates usually are plastic platforms such as PET, polyimide (PI), polyethylene naphthalate (PEN) and polycarbonate (PC). Other flexible substrates include textile [51,52], silk [53,54], paper [55][56][57][58], metalfoil [59,60], shape-memory polymer [61][62][63] and so on. Besides, weavable and fiber-like electrode [17,64]/device configurations [65][66][67][68][69], or even substrate-free free-standing configurations [70] are also demonstrated as effective ways for obtaining flexible devices.…”