The Stratakis Lab

The Stratakis Lab

Ultrafast Laser Micro and Nano Processing Laboratory

Advanced Composite Glasses for Optoelectronics

Objective: This research topic aims at the development of advanced composite glasses for optoelectronic applications.

Abstract: Over the years, the importance of inorganic oxide glasses in various fields of photonics and solid state electrochemical technological applications has been demonstrated. A continuous scientific challenge lies on maximizing the functionality of novel glassy materials, and thus expanding their potential towards modern optoelectronic applications and devices. In this research activity we aim at the development of advanced composite glasses by means of incorporating crystalline materials and metallic particles, as well as, by laser processing of super-soft inorganic glasses. As for instance, upon following specific preparation and annealing protocols we were able to induce second harmonic generation (SHG) and nonlinear optical features in a series of silver-rich phosphate glasses. Moreover, nonlinear laser imaging microscopy is employed in order to explicitly study the dynamics of SHG (Figure 1) upon varying glass composition and temperature. On a rather different approach, ultrashort pulsed laser processing is performed on the surface of silver phosphate glass (AgPO3). The selection of AgPO3 glass offers a remarkable advantage in terms of allowing the fabrication of high regularity, erasable and rewritable periodic surface patterns (Figure 2). Remarkably, the developed write/erase/re-write process on the same glass area is based on a single laser beam, thus, rendering the silver phosphate glass an important candidate for waveguides and optical responsive memory components. Finally, ongoing work involves the development of composite glasses upon encapsulating a variety of inorganic perovskite and 2D materials, while tuning the photoluminescence properties of the so-formed glasses.

Figure 1: Photo of second harmonic generation (SHG) signal exhibited by AgPO3 glass (left), and SHG signal intensity of xAgI-(1-x)AgPO3 glasses (right). The inset depicts a typical AgPO3 glass sample.

Figure 2: Schematic representations of the laser processing experimental setup, and the write/erase/re-write procedure of the high regularity periodic surface patterns.

Selected publications:

1. “Effect of composition and temperature on the second harmonic generation in silver phosphate glasses”, I. Konidakis, S. Psilodimitrakopoulos, K. Kosma, A. Lemonis and E. Stratakis, Opt. Mater. 75, 796 (2018).

2. “Erasable and rewritable laser-induced gratings on silver phosphate glass”, I. Konidakis, E. Skoulas, A. Papadopoulos, E. Serpetzoglou, E. Margariti and E. Stratakis, Appl. Phys. A 124, 839 (2018).

3. “Vibrational spectroscopic and bond valence study of structure and bonding in Al2O3-containing AgI-AgPO3 glasses”, D. Palles, I. Konidakis, C.P.E. Varsamis and E.I. Kamitsos, RSC Adv. 6, 16697 (2016).

Project members:

Dr. Emmanuel Stratakis

Dr. Ioannis Konidakis

Dr. Abdus S. Sarkar

Dr. Sotiris Psilodimitrakopoulos

Mr. Evangelos Skoulas

Mr. Andreas Lemonis

Ms. Ioanna Demeridou.

Collaborators: Prof. George.