Blue quantum electroabsorption modulators based on reversed quantum confined Stark effect with blueshift

The authors present the design, growth, fabrication, experimental characterization, and theoretical analysis of blue quantum electroabsorption modulators that incorporate ∼5nm thick In0.35Ga0.65N∕GaN quantum structures for operation between 420 and 430nm. Growing on polar c plane on sapphire, they obtain quantum structures with zigzag potential profile due to alternating polarization fields and demonstrate that their optical absorption blueshifts with applied electric field, unlike the redshift of conventional quantum confined Stark effect. In InGaN∕GaN quantum structures, they report the largest absorption change of 6000cm−1 for 6V bias swing around 424nm, holding promise for blue optical clock generation and injection directly into silicon chips.