Luminescence confocal microscopy of 3D components of photonic integrated circuits fabricated by two-photon photopolymerization

Direct laser writing (DLW) lithography has been growing rapidly and is widely used for photonic integrated circuit (PIC) fabrication manufacturing in micro optics and photonics to fabricate 2D, 2.5D, and 3D components due to low cost, high precision and no need for mask exposure. There is a huge demand for PIC for instruments, systems and complexes of optoelectronic navigation instrumentation, as well as for use in a wide range of areas: biophotonics, signal detection and processing, robotics, telecommunications. The technique of DLW is based on nonlinear interaction between laser radiation and the photoresist medium (two photon absorption and consequent photopolymerization). The traditional method for studying the morphology of obtained PIC elements is the method of scanning electron microscopy. An alternative method of morphological analysis of PICs obtained by two photon absorption-direct laser writing (TPA-DLW) is proposed here - scanning luminescence confocal microscopy method. It is an effective method that enables obtaining conclusive information on the geometrical parameters as the morphology properties as well as the luminescence information. (C) 2021 Vietnam National University, Hanoi. Published by Elsevier B.V.

Automated summary

Direct laser writing (DLW) lithography is a rapidly growing and widely used technique in the field of photonics. It offers low cost, high precision, and eliminates the need for mask exposure. DLW enables the fabrication of 2D, 2.5D, and 3D components, meeting the demand for photonic integrated circuits (PICs) in various areas such as optoelectronic navigation instrumentation, biophotonics, signal detection and processing, robotics, and telecommunications. This article proposes an alternative method, scanning luminescence confocal microscopy, for morphological analysis of PICs obtained by two photon absorption-direct laser writing (TPA-DLW), which provides conclusive information on geometrical parameters, morphology properties, and luminescence information.