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A pair of nanostructured mirrors made of a diffraction grating inscribed in the top layer of a Bragg mirror are designed such that a phase shift near π and different reflected amplitudes exist between transverse electric (TE) and magnetic (TM) reflected polarization states at normal incidence. When a standing wave laser resonator is formed with two such mirrors and the two mirrors’ principal axes are twisted one with respect to the other, this phase shift condition suppresses multiple longitudinal mode emission arising from axial spatial hole burning. In addition, the different amplitudes of TE and TM reflected polarizations create polarization eigenstates with different round-trip losses, suppressing one polarization eigenstate. Laser experiments made with a Yb3+-doped Y3Al5O12 active material reveal enhanced purity of the emission spectrum compared to similar lasers using conventional laser mirrors. The proposed design enables a miniature single mode laser, replacing more complex designs usually needed to achieve that goal.

We present the intracavity generation of beams with radial polarization at an average output power of 750 W and an optical efficiency of 43% from a continuous wave thin-disk laser. Circular grating waveguide output couplers (GWOC) were used to select the radial polarization. The sensitivity of the polarizing function of the GWOC with regards to the fabrication tolerances is also analysed in details with a particular emphasis on the effect of the duty cycle and the geometrical profile of the gratings. Furthermore, we present the conversion of femtosecond laser pulses from linear to azimuthal polarization using a nanograting-based polarization converter. Azimuthally polarized beams with an average power of up to 850 W, a pulse duration of 400 fs and a pulse repetition rate of 1 MHz were generated in this way with a conversion efficiency of >90%.

32-channel arrayed waveguide grating spectrometer (AWG) at 1800 nm is demonstrated on a 2-µm-thick silicon-on-insulator (SOI) platform. The design and simulation of the device are performed using the beam propagation method (BPM) and we obtain the 3-dB channel width, channel spacing, and extinction ratio of 1.16 nm, 1.56 nm, and 5.17 dB, respectively. The AWG demultiplexer can be applied in the central part of a spectrometer which is replacing in integrated optics a prism or a grating in conventional free-space optics.

We demonstrate the integration of arrayed waveguide grating (AWG) de-multiplexer with a low loss and low index contrast platform, i.e., a striped-loaded slot waveguide (SLWG). The SLSW-AWG is designed to operate around the wavelength λ = 1550 nm with a four-output channel. The device experiences excellent output parameters: channel width δλ = 1.39 nm at -3dB, channel spacing Δλ = 2.43 nm and extinction ratio ER = 9.87 dB, useful for sensing applications.

An optimized achromatic high-efficiency monolithic phase mask is presented whose principle was demonstrated and described in reference [1]. The mask comprises three submicron period diffraction gratings at a single substrate side that create a purely single spatial frequency interferogram of large period. The optical scheme is that of an integrated Mach-Zehnder interferometer where all light circulation functions are performed by diffraction gratings. The paper describes the operation principle of the phase mask, the fabrication process, and its utilization in a write-on-the-fly scheme for the writing of a long, 2 μm-period grating.