In this paper, the first demonstration of simultaneous UV written Bragg gratings and waveguides in germanium and boron-doped planar silica is presented using a 5th harmonic solid-state nanosecond laser operating at 213 nm wavelength. The fabrication of high-quality gratings by using a high peak power density, yielding sufficient uniformity and without any surface damage is demonstrated. The photosensitivity of the doped silica layer is investigated by measuring the local effective refractive

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... ex of the optical modes. The written gratings are used to measure grating refractive index modulation, grating detuning bandwidth and the waveguide propagation loss with a minimum value of 0.28 ± 0.07 dB cm −1 . This paper shows that this new generation of pulsed UV lasers is a promising alternative for conventional longer wavelength CW laser sources used in small spot direct grating writing in doped silica. Introduction: Bragg gratings in planar silica provide functionality for various integrated devices such as optical sensors [1], grating stabilized semiconductor lasers [2], and add-drop filter components [3] . Bragg grating based devices are usually fabricated using conventional lithography and etching to form both the waveguide and grating structures. Etched grating components typically require a precise definition of the waveguide dimensions and the grating period-demanding extremely high fabrication accuracy. The limitations of lithography and etching have led researchers to look to alternative approaches such as phase mask [4] and direct writing techniques, including femtosecond [5] and UV laser writing [1] . Femtosecond writing provides a unique ability to fabricate 3D photonic structures [6] but has its challenges due to nonuniformity originating from nonlinear laser interaction. Direct UV writing (DUW) has unique benefits for defining both channel waveguides and Bragg gratings in doped planar silica with minimal losses [7, 8] . Typically, DUW and direct grating writing (DGW) employ a 244 nm frequency-doubled argon-ion laser and rely on the photosensitivity of planar silica achieved by doping with germanium and boron to induce a change in refractive index. Additionally, the doped silica layers often require in-diffusion of hydrogen or deuterium before UV writing to ensure adequate refractive index change [9] . For commercial implementation, there is a need to reduce the manufacturing and maintenance cost of direct UV writing setups. Conventional laser sources for UV writing are usually costly to run and maintain; therefore, new high-efficiency, low-maintenance sources are desirable. The first use of a 213 nm quintupled Nd-YAG laser source to induce a refractive index change in planar silica was by Schenker et al. [10], with further studies exploring the use of picosecond pulses to UV trim fibre Bragg gratings [11] . More recently, fifth harmonic solid-state Nd: YVO 4 lasers, operating at a wavelength of 213 nm, have become commercially available, providing nanosecond pulses with high peak power. Compared with conventional lasers, these sources are compact, cost-effective, and efficient in terms of footprint, power consumption and maintenance. These laser sources have been employed to fabricate Bragg gratings in hydrogen-free SMF-28 fibre using a phase mask technique [4] . The relatively long coherence lengths available from such commercial systems permit the flexibility of the dual-beam interferometer arrangement [12] suggesting such systems may be suitable for DGW. Recently single-mode waveguides have been fabricated in hydrogenloaded and non-hydrogen loaded planar silica by single-beam 213 nm inscription [13, 14] . Some preliminary results on simultaneously produced Bragg gratings and waveguides by 213 nm light were reported