A tunable ring laser having a ring cavity, wherein the ring cavity comprises: a ring resonator having a waveguide; a phase modulator having a waveguide; a power coupler coupled to the ring resonator; and a reflector, to reflect an anti-clock-wise mode or reflect a clock-wise mode, such that a propagation direction of a mode of the tunable ring laser is unidirectional, wherein a cross section of the waveguide of at least one of the ring resonator or the phase modulator is config-ured as an electro-refractive modulator such that the tunable ring laser is tunable by applying a reverse bias voltage to at least one of the waveguide of the ring resonator or the waveguide of the phase modulator respectively.

A method of operating a tunable ring laser, wherein the method comprises: coupling, by a power coupler, a first light wave and a second light wave in a ring resonator; guiding, by the ring resonator and a phase modulator, a first light wave and a second light wave via at least one of a waveguide of the ring resonator or a waveguide of the phase modulator respectively, wherein a cross sec-tion of the waveguide of at least one of the ring resonator or the phase modulator respectively is con-figured as an electro-refractive modulator, applying, to at least one of the waveguide of the ring resonator or the waveguide of the phase modulator respectively, a reverse bias voltage to tune the tunable ring laser, and reflecting, by a reflector, an anti-clock-wise mode or a clock-wise mode, such that a propagation direction of a mode of the tunable ring laser is unidirectional.

A method of fabricating a tunable ring laser having a ring cavity, the method comprising: at least partly providing a ring resonator having a wave-guide; at least partly providing a phase modulator having a waveguide; at least partly providing a power coupler coupled to the resonator; and at least partly providing a reflector to reflect an anti-clock-wise mode or a clock-wise mode, such that a propaga-tion direction of a mode of the tunable ring laser is unidirectional, wherein a cross section of the waveguide of at least one of the ring resonator or the phase modulator is config-ured as an electro-refractive modulator such that the tunable ring laser is tunable by applying a reverse bias voltage to at least one of the waveguide of the ring resonator or the waveguide of the phase modulator respectively.

A tunable ring laser having a ring cavity, wherein the ring cavity comprises: a ring resonator having a waveguide; a phase modulator having a waveguide; a power coupler coupled to the ring resonator; and a reflector, to reflect an anti-clock-wise mode or reflect a clock-wise mode, such that a propagation direction of a mode of the tunable ring laser is unidirectional, wherein a cross section of the waveguide of at least one of the ring resonator or the phase modulator is config-ured as an electro-refractive modulator such that the tunable ring laser is tunable by applying a reverse bias voltage to at least one of the waveguide of the ring resonator or the waveguide of the phase modulator respectively.

A method of operating a tunable ring laser, wherein the method comprises: coupling, by a power coupler, a first light wave and a second light wave in a ring resonator; guiding, by the ring resonator and a phase modulator, a first light wave and a second light wave via at least one of a waveguide of the ring resonator or a waveguide of the phase modulator respectively, wherein a cross sec-tion of the waveguide of at least one of the ring resonator or the phase modulator respectively is con-figured as an electro-refractive modulator, applying, to at least one of the waveguide of the ring resonator or the waveguide of the phase modulator respectively, a reverse bias voltage to tune the tunable ring laser, and reflecting, by a reflector, an anti-clock-wise mode or a clock-wise mode, such that a propagation direction of a mode of the tunable ring laser is unidirectional.

A method of fabricating a tunable ring laser having a ring cavity, the method comprising: at least partly providing a ring resonator having a wave-guide; at least partly providing a phase modulator having a waveguide; at least partly providing a power coupler coupled to the resonator; and at least partly providing a reflector to reflect an anti-clock-wise mode or a clock-wise mode, such that a propaga-tion direction of a mode of the tunable ring laser is unidirectional, wherein a cross section of the waveguide of at least one of the ring resonator or the phase modulator is config-ured as an electro-refractive modulator such that the tunable ring laser is tunable by applying a reverse bias voltage to at least one of the waveguide of the ring resonator or the waveguide of the phase modulator respectively.

A tunable ring laser having a ring cavity, wherein the ring cavity comprises: a ring resonator having a waveguide; a phase modulator having a waveguide; a power coupler coupled to the ring resonator; and a reflector, to reflect an anti-clock-wise mode or reflect a clock-wise mode, such that a propagation direction of a mode of the tunable ring laser is unidirectional, wherein a cross section of the waveguide of at least one of the ring resonator or the phase modulator is config-ured as an electro-refractive modulator such that the tunable ring laser is tunable by applying a reverse bias voltage to at least one of the waveguide of the ring resonator or the waveguide of the phase modulator respectively.

A method of operating a tunable ring laser, wherein the method comprises: coupling, by a power coupler, a first light wave and a second light wave in a ring resonator; guiding, by the ring resonator and a phase modulator, a first light wave and a second light wave via at least one of a waveguide of the ring resonator or a waveguide of the phase modulator respectively, wherein a cross sec-tion of the waveguide of at least one of the ring resonator or the phase modulator respectively is con-figured as an electro-refractive modulator, applying, to at least one of the waveguide of the ring resonator or the waveguide of the phase modulator respectively, a reverse bias voltage to tune the tunable ring laser, and reflecting, by a reflector, an anti-clock-wise mode or a clock-wise mode, such that a propagation direction of a mode of the tunable ring laser is unidirectional.

A method of fabricating a tunable ring laser having a ring cavity, the method comprising: at least partly providing a ring resonator having a wave-guide; at least partly providing a phase modulator having a waveguide; at least partly providing a power coupler coupled to the resonator; and at least partly providing a reflector to reflect an anti-clock-wise mode or a clock-wise mode, such that a propaga-tion direction of a mode of the tunable ring laser is unidirectional, wherein a cross section of the waveguide of at least one of the ring resonator or the phase modulator is config-ured as an electro-refractive modulator such that the tunable ring laser is tunable by applying a reverse bias voltage to at least one of the waveguide of the ring resonator or the waveguide of the phase modulator respectively.

A tunable ring laser having a ring cavity, wherein the ring cavity comprises: a ring resonator having a waveguide; a phase modulator having a waveguide; a power coupler coupled to the ring resonator; and a reflector, to reflect an anti-clock-wise mode or reflect a clock-wise mode, such that a propagation direction of a mode of the tunable ring laser is unidirectional, wherein a cross section of the waveguide of at least one of the ring resonator or the phase modulator is config-ured as an electro-refractive modulator such that the tunable ring laser is tunable by applying a reverse bias voltage to at least one of the waveguide of the ring resonator or the waveguide of the phase modulator respectively.

A method of operating a tunable ring laser, wherein the method comprises: coupling, by a power coupler, a first light wave and a second light wave in a ring resonator; guiding, by the ring resonator and a phase modulator, a first light wave and a second light wave via at least one of a waveguide of the ring resonator or a waveguide of the phase modulator respectively, wherein a cross sec-tion of the waveguide of at least one of the ring resonator or the phase modulator respectively is con-figured as an electro-refractive modulator, applying, to at least one of the waveguide of the ring resonator or the waveguide of the phase modulator respectively, a reverse bias voltage to tune the tunable ring laser, and reflecting, by a reflector, an anti-clock-wise mode or a clock-wise mode, such that a propagation direction of a mode of the tunable ring laser is unidirectional.

A method of fabricating a tunable ring laser having a ring cavity, the method comprising: at least partly providing a ring resonator having a wave-guide; at least partly providing a phase modulator having a waveguide; at least partly providing a power coupler coupled to the resonator; and at least partly providing a reflector to reflect an anti-clock-wise mode or a clock-wise mode, such that a propaga-tion direction of a mode of the tunable ring laser is unidirectional, wherein a cross section of the waveguide of at least one of the ring resonator or the phase modulator is config-ured as an electro-refractive modulator such that the tunable ring laser is tunable by applying a reverse bias voltage to at least one of the waveguide of the ring resonator or the waveguide of the phase modulator respectively.