Poly(para-phenylene vinylene) (PPV) is a key material for optoelectronics because it combines the potential of both polymers and semiconductors. PPV has been synthesized via solution-processable precursor route, in which the precursor polymer poly(xylene tetrahydrothiophenium chloride) (PTHT) is thermally converted to PPV throughout the sample as a whole. Much effort has been devoted to fulfill spatial selectivity of PPV conversion. However, none of the methods proposed stand for PPV conversion three dimensionally, which would be appealing for the design of microdevices. Here, we demonstrate the potential of fs-laser direct writing via two-photon polymerization (2PP) to fabricate PPV-doped 3D microstructures. PTHT is incorporated into the polymeric material and it is subsequently converted to PPV through a thermal treatment. Optical measurements, taken prior and after thermal conversion, confirm the PTHT to PPV conversion. Fs-laser direct writing via 2PP can be exploited to fabricate a variety of 3D microdevices, thus opening new avenues in polymer-based optoelectronics.

The emerging fabrication techniques for transparent materials such as glass and crystal that use focused ultra-short laser pulses will be reviewed from the viewpoint of functionalities of the products to be integrated into a future photonic system. The devices include waveguide and waveguide couplers, mirrors and lenses, filters and holograms. The future photonic system may consist of many functional subsystems which are connected through transparent gates or windows. Welding technique may play an important role for this system integration. The welding technique for transparent materials using ultra-short laser pulses will also be reviewed along with applications to hermetic sealing. The author presents experimental results on the temperature dynamics. The author will also discuss on an idea connecting the relaxation of internal stress and the high index change and a role of the void and its motion in the fabrication process. The bright near future and challenges of the glass processing techniques with ultrafast lasers will briefly be touched on.

Conversion of PTHT into PPV is achieved by direct laser writing. Fs-laser pulses induce photo-thermal reactions due to two-photon absorption, resulting in the microscopic control of PPV polymerization. Such methodology is a promising way towards the fabrication of arbitrary polymeric microcircuits.

Conjugated polymers are important materials for optical applications, among which poly(p‐phenylene vinylene) (PPV) has a major role due to its applicability in sensors, organic light‐emitting diodes and large area displays. Despite advances on the synthesis of PPV‐based polymers and the improvements of their properties, its printing process, in particular involving the solid phase, remains unsuitable for the development of electro‐optical microcircuits. This paper demonstrates the printing of PPV from the solid phase in 2D micropatterns. Such an achievement was performed using laser induced forward transfer with femtosecond pulses, which allows area‐selective deposition within reduced scales as thin as ca 100 nm and 5 µm wide. Raman, fluorescence and electrochemical impedance spectroscopies confirm that the printed PPV micropatterns have the same structure, emission spectrum and conductivity as the target material, revealing the conservation of their original properties even after laser irradiation. The printing process was carried out using PPV films, overcoming the insolubility issue of this material. The optical and electrical characterization of the transferred PPV demonstrates the potential of this method for the patterning of electro‐optical microdevices, since luminescence and electrical conductivity were preserved. © 2018 Society of Chemical Industry