Optical splitter , comprising: a tapered first waveguide configured to receive a multimode optical signal at its base and propagate the multimode signal towards its tip, wherein the multimode optical signal includes a fundamental transverse electric, TE, mode and a first order TE mode; and two tapered second waveguides arranged in parallel on different sides of the first waveguide , each second waveguide being oppositely tapered than the first waveguide and being configured to propagate a single mode optical signal towards its base and output the single mode optical signal at its base, wherein each single mode optical signal includes a fundamental TE mode, wherein the optical splitter is configured to adiabatically split the multimode optical signal propagating in the first waveguide towards its tip into the two single mode optical signals propagating in the second waveguides towards their bases, wherein the first waveguide and the second waveguides are made of SiN, wherein the first waveguide and the second waveguides are embedded into a SiO 2 cladding, wherein a height of the first waveguide and of the two second waveguides is, respectively, 400 nm, wherein a width of the base of the first waveguide is 1.2 μm, wherein a width of the bases of the two second waveguides is 800 nm, respectively, wherein a width of the tip of the first waveguide and of the tips of the two second waveguides is 200 nm, respectively, wherein a gap between the first waveguide and each second waveguide at the tips of the second waveguides is 200 nm, and wherein a gap between the first waveguide and each second waveguide at the tip of the first waveguide is 400-600 nm. a tapered first waveguide configured to receive a multimode optical signal at its base and propagate the multimode signal towards its tip, wherein the multimode optical signal includes a fundamental transverse electric, TE, mode and a first order TE mode; and two tapered second waveguides arranged in parallel on different sides of the first waveguide , each second waveguide being oppositely tapered than the first waveguide and being configured to propagate a single mode optical signal towards its base and output the single mode optical signal at its base, wherein each single mode optical signal includes a fundamental TE mode, wherein the optical splitter is configured to adiabatically split the multimode optical signal propagating in the first waveguide towards its tip into the two single mode optical signals propagating in the second waveguides towards their bases, wherein the first waveguide and the second waveguides are made of SiN, wherein the first waveguide and the second waveguides are embedded into a SiO 2 cladding, wherein a height of the first waveguide and of the two second waveguides is, respectively, 400 nm, wherein a width of the base of the first waveguide is 1.2 μm, wherein a width of the bases of the two second waveguides is 800 nm, respectively, wherein a width of the tip of the first waveguide and of the tips of the two second waveguides is 200 nm, respectively, wherein a gap between the first waveguide and each second waveguide at the tips of the second waveguides is 200 nm, and wherein a gap between the first waveguide and each second waveguide at the tip of the first waveguide is 400-600 nm. <EOS>