Semiconductor structure, including: ∘ a semiconductor layer made of a crystalline semiconductor compound, including a membrane suspended above a carrier layer, the suspended membrane being formed: • of a central section, which is tensilely stressed in a plane parallel to the carrier layer, and which forms a waveguide able to support at least one optical mode (TE00, TE01; TM00, TM01); and • of a plurality of lateral sections, which are opposite one another with respect to the central section, and which are arranged so as to keep the central section suspended and tensilely stressed, the lateral sections having an average width larger than an average width of the central section; and ∘ at least one optical cavity, bounded by: • two optical reflectors, which are placed in the lateral sections on either side of the central section; characterized in that: • the central section is designed to transmit in the direction of the optical reflectors at least one uneven-order mode (TE01; TM01); and • each of said optical reflectors is formed of two lateral half-reflectors, which are separate from one another and arranged on either side of a longitudinal axis (Δ) of the lateral section in which they are placed, so as to at least partially reflect said uneven-order mode (TE01; TM01). ∘ a semiconductor layer made of a crystalline semiconductor compound, including a membrane suspended above a carrier layer, the suspended membrane being formed: • of a central section, which is tensilely stressed in a plane parallel to the carrier layer, and which forms a waveguide able to support at least one optical mode (TE00, TE01; TM00, TM01); and • of a plurality of lateral sections, which are opposite one another with respect to the central section, and which are arranged so as to keep the central section suspended and tensilely stressed, the lateral sections having an average width larger than an average width of the central section; and • of a central section, which is tensilely stressed in a plane parallel to the carrier layer, and which forms a waveguide able to support at least one optical mode (TE00, TE01; TM00, TM01); and • of a plurality of lateral sections, which are opposite one another with respect to the central section, and which are arranged so as to keep the central section suspended and tensilely stressed, the lateral sections having an average width larger than an average width of the central section; and ∘ at least one optical cavity, bounded by: • two optical reflectors, which are placed in the lateral sections on either side of the central section; characterized in that: • the central section is designed to transmit in the direction of the optical reflectors at least one uneven-order mode (TE01; TM01); and • each of said optical reflectors is formed of two lateral half-reflectors, which are separate from one another and arranged on either side of a longitudinal axis (Δ) of the lateral section in which they are placed, so as to at least partially reflect said uneven-order mode (TE01; TM01). • two optical reflectors, which are placed in the lateral sections on either side of the central section; • the central section is designed to transmit in the direction of the optical reflectors at least one uneven-order mode (TE01; TM01); and • each of said optical reflectors is formed of two lateral half-reflectors, which are separate from one another and arranged on either side of a longitudinal axis (Δ) of the lateral section in which they are placed, so as to at least partially reflect said uneven-order mode (TE01; TM01).