Wavelength-tunable optoelectronic apparatus

A wavelength-tunable optoelectronic apparatus comprising:

• a bulk semiconductor layer of conductivity type I;
• a bulk semiconductor layer of conductivity type II;
• at least one optical waveguide, each of the at least one optical waveguide being individually bent in an x-y plane, the x-y plane being defined by an x-axis in an x-direction and a y-axis in a y-direction, each of the at least one optical waveguide defining a respective axial direction;
• at least one active layer including at least one active layer portion, each of the at least one active layer portion being associated with a respective one of the at least one optical waveguide, charge carriers of at least one of conductivity types I and II being injected into at least one of the at least one active layer portion;
• at least one feedback grating having a grating area, the grating area having a length L in the x-direction and including a left and a right boundary surface perpendicular to the x-axis, the left boundary surface being disposed at a left end of the grating area at an x=0 position and the right boundary surface being disposed at a right end of the grating at an x=L position, with respect to the x-axis;
• a contacting arrangement having at least one contacting portion, each of the at least one contacting portion being disposed over an associated one of the at least one optical waveguide and extending discontinuously in a respective plurality of sections in the respective axial direction at a side of the bulk semiconductor layer of conductivity type I, each section of each respective plurality of sections having a respective associated contact pad, the contacting arrangement extending continuously in the respective axial direction at a side of the bulk semiconductor layer of conductivity type II;
• and
• at least one isolation trench, each of the at least one isolation trench being disposed over a respective at least one of the at least one optical waveguide, each of the at least one isolation trench being disposed between and bounding a respective at least one pair of sections of at least one of the respective plurality of sections of at least one of the at least one contacting portion, a depth, a width, a lateral position and a material of each of the at least one isolation trench being dimensioned to provide an ohmic resistance of at least 10 ohms between the respective at least one pair of sections so as to enable each section of each of the respective plurality of sections of the at least one contacting portion to be supplied with an individually adjustable current via the respective associated contact pad;
• when a respective potential of each of the respective associated contact pads is equal to the respective potential of each of the other respective associated contact pads, a respective bending function of each of the at least one optical waveguide being determined by the following conditions:
• the respective at least one optical waveguide having at least three spectrally adjacent modes of an index ji, a respective threshold gain of each of the at least three spectrally adjacent modes being lower than other modes of the respective at least one optical waveguide, i being an ordinal number of the respective at least one optical waveguide;
• the respective threshold gain αth,ji,i of each of the at least three spectrally adjacent modes differ from each other by no more than 4% of their absolute values, each of the respective threshold gains differing from the other modes of the respective at least one optical waveguide by at least 8%, where ji=1,2, . . . mi mi being a number of spectrally adjacent modes of the respective at least one optical waveguide of ordinal number i, where ji is a whole number integer selected from a range of l to mi;
• and
• a respective spectrum of the at least one optical waveguide having exactly ji spectrally adjacent modes extending over a respective wavelength range Δλi=λmax,i-λmin,i, λmax,i and λmin,i being a respective maximum and minimum wavelength of the respective wavelength range Δλi, where i is an integer in a first range 1≦i≦n, n being a number of the at least one optical waveguide;
• a total operating wavelength range of the wavelength-tunable optoelectronic apparatus including the respective wavelength range Δλi of each of the at least one optical waveguide, the respective wavelength range of the at least one optical waveguide being describable spectrally by the relationship |λmax,k−λmin,k+1|<(Δλk+Δλk+1)/10, where k is an integer in a second range 1≦k≦(n−1).