Patent ID: 8543961

Claim:
A method for designing an electro-optical modulator device to operate in a coupling mode or a detection mode in which light having a wavelength λ is incident upon a semiconductor structure comprised by the electro-optical modulator device at an incident angle (θ i ) with respect to a direction opposite to a Z direction, said method comprising: receiving input, by a processor of a computer system, for designing the electro-optical modulator device to operate in the coupling mode or the detection mode, wherein the semiconductor structure comprises a semiconductor layer having a thickness (r) in the Z direction and a plurality of grating structures on a top surface of the semiconductor layer, wherein the Z direction is perpendicular to the top surface of the semiconductor layer, wherein the semiconductor layer comprises a plurality of semiconductor channel regions, wherein the grating structures are distributed in a periodic pattern having a pitch (p 1 ) in an X direction that is orthogonal to the Z direction, wherein each grating structure comprises a notch and is above a corresponding channel region of the plurality of semiconductor channel regions and has a height (h g ) in the Z direction above the top surface of the semiconductor layer, wherein each notch comprises a width (w 1 ) in the X direction, wherein a voltage V applied between each notch and a corresponding doped semiconductor region in the semiconductor layer induces a change Δa of an absorption coefficient (a) and a change Δn of an index of refraction of a semiconductor domain comprising each notch and its corresponding channel region to generate a changed absorption coefficient and a changed index of refraction of the semiconductor domain, and wherein said receiving input comprises receiving a value of λ, r, h g , an absorption coefficient threshold (A th1 ), an index of refraction threshold (n th1 ), and acceptance criteria; said processor ascertaining P solution sets at which the electro-optical modulator device operates in an ON state in which V=V 1 for causing the changed absorption coefficient to exceed A th1 and causing the changed index of refraction to exceed n th1 and at which the acceptance criteria are satisfied, wherein said ascertaining comprises calculating Δa according to Δa(V) and calculating Δn according to Δn(V), wherein Δa(V) is a specified function of V and Δn(V) is a specified function of V, wherein each solution set of the P solution sets comprises p 1 , w 1 , θ 1 , and V 1 , and wherein P≧1; determining a design set for the ON state; said processor transmitting the design set for the ON state to an output device.