From Large Telescopes to Tiny Chips: Astrophotonic Perspectives for the VLT/I

While telescopes are becoming larger to increase sensitivity and angular resolution, astrophotonic devices pursue the opposite approach, enabling compact instruments with stable and versatile architectures. In this presentation, I will review recent developments in astrophotonics that could enhance the capabilities of the VLT and VLTI in the near future. Ongoing efforts focus on the design of short-wavelength beam combiners, which require advanced fabrication technologies to achieve high-performance integrated optics chips with low insertion and propagation losses, as well as reliable polarization control. Moreover, integrated optics offer a wide range of functionalities, such as on-chip active phase control, or complex routing schemes like the back-propagation of a metrology laser source, enabling precise measurement of the instrumental phase (could be used for an upgrade of the GRAVITY metrology system). Finally, astrophotonic devices such as photonic lanterns provide an efficient way to decompose the incident telescope beam with high photon efficiency. These devices could significantly strengthen the VLT capabilities in areas such as wavefront sensing and high-angular-resolution spectro-astrometric imaging.