Light source and method for controlling the same

A light source for operation in terahertz frequency region, the light source comprising:

• a coherent light generator arrangement configured to generate at least one output light;
• and
• a waveguide arrangement optically coupled to the coherent light generator arrangement, the waveguide arrangement comprising:
• a first surface portion and a second surface portion;
• at least one first resonator element and at least one second resonator element arranged in different orientations, each of the at least one first resonator element and the at least one second resonator element having an elongated shape,
• wherein the at least one first resonator element protrudes from the first surface portion and the at least one second resonator element protrudes from the second surface portion,
• wherein the waveguide arrangement is configured to interact with the at least one output light to cause the at least one first resonator element and the at least one second resonator element to emit respective first and second optical signals that are linearly polarized along respective longitudinal axes of the elongated shapes of the at least one first resonator element and the at least one second resonator element to co-operatively interact with each other to generate an output optical signal, and
• wherein the light source is configured to change a polarization characteristic of the output optical signal in response to at least one electrical signal applied to the light source to vary at least one of respective magnitudes of the first and second optical signals relative to each other.