Abstract This corrigendum resolves an error in the plot of quality factors as a function of number of air holes in figure 5(a) and its caption. In the original version, the symbols for the plot of quality factors before and after optimization were mistakenly interchanged, and the caption mentioned a wrong symbol. In the correct version below, blue rectangles have been replaced with blue stars and vice versa. The caption ‘Figure 5. (a)Plot of coupling efficiency (left) and quality factor (right) as a function of number of air holes for the cavity-waveguide system before (solid rectangles) and after (hollow triangles) optimizing the termination region.’ has been changed to ‘Figure 5. (a) Plot of coupling efficiency (left) and quality factor (right) as a function of number of air holes for the cavity-waveguide system before (solid rectangles) and after (solid stars) optimizing the termination region.’ Their interpretation remains unchanged.