Electrorefraction in GaAs and InGaAsP and its application to phase modulators

A Kramers–Kronig analysis is used to calculate the refractive index change induced by changes in the shape of the fundamental absorption edge when a strong electric field is applied to a semiconductor. Calculations are made for GaAs and InGaAsP over the 0.9 to 1.55 μm wavelength range. For GaAs, we find that the electrorefraction is Δn=7.9×10−4 at λ=1.06 μm when the electric field is 400 kV/cm, but decreases to Δn=1.3×10−4 at λ=1.55 μm for the same electric field strength. For wavelengths far below the band gap, the refractive index change has a quadratic dependence on the applied electric field. The electrorefraction effect will have important applications for optical waveguide phase modulators.

[1]  L. Coldren,et al.  Highly efficient waveguide phase modulator for integrated optoelectronics , 1986 .

[2]  J. Callaway.  Optical Absorption in an Electric Field , 1963 .

[3]  S. Akiba,et al.  Dynamic spectral width of an InGaAsP/InP electroabsorption light modulator under high-frequency large-signal modulation , 1986 .

[4]  Wood,et al.  Electric field dependence of optical absorption near the band gap of quantum-well structures. , 1985, Physical review. B, Condensed matter.

[5]  H. Casey,et al.  Heterostructure lasers , 1978 .

[6]  G. E. Stillman,et al.  Electroabsorption in GaAs and its application to waveguide detectors and modulators , 1976 .

[7]  E. Kane,et al.  Band structure of indium antimonide , 1957 .

[8]  H. C. Casey,et al.  Concentration dependence of the absorption coefficient for n− and p−type GaAs between 1.3 and 1.6 eV , 1975 .

[9]  F. K. Reinhart,et al.  Electro‐optical light modulation in InGaAsP/InP double heterostructure diodes , 1983 .

[10]  H. Okamoto,et al.  Optical Absorption Characteristics of GaAs–AlGaAs Multi-Quantum-Well Heterostructure Waveguides , 1983 .

[11]  N. Bottka,et al.  Franz-Keldysh Effect of the Refractive Index in Semiconductors , 1965 .

[12]  K. Tharmalingam.  Optical Absorption in the Presence of a Uniform Field , 1963 .

[13]  R. H. Kingston.  Electroabsorption in GaInAsP , 1979 .

[14]  H. Wieder,et al.  Franz–Keldysh electrorefraction and electroabsorption in bulk InP and GaAs , 1986 .

[15]  H. Haus.  Waves and fields in optoelectronics , 1983 .

[16]  Kenichi Iga,et al.  Frequency chirping of external modulation and its reduction , 1985 .

[17]  Frank Stern,et al.  Dispersion of the Index of Refraction Near the Absorption Edge of Semiconductors , 1964 .