Electroabsorption in InGaAsP-InP double heterostructures

This letter reports the measurements of electroabsorption in InGaAsP-InP double heterostructures for electric fields in the range of 10¿300 kV/cm. The absorption of the waveguide modes is very large (-40 cm¿1 cm at¿5 V applied bias) for photon energies ~;100 meV from the bandgap The electro-absorption is polarisation dependent. The absorption for light polarised along the field (TM-mode) is larger than that for light polarised normal to the field (TE-mode). The electroabsorption effect can be used to produce light amplitude modulators, polarisers and photodetectors.