In the development of ultrafast optics over the past decade, photoluminescence (PL) has been used as an effective tool to reflect the THz-electroninteraction and modulation. The PL signals are always time-integrated from bulk semiconductors or time-resolved from low temperature quantum wells. They reflect the THz-electron interaction to a certain extent, and however, are insufficient to represent the THz wave in time domain.
Under the guidance of Prof. Jinsong Liu, Dr. Chu in Nonlinear Terahertz Laboratory of WNLO, using biased bulk semiconductor as receiver, developed a THz wave detection methodvia photoluminescence. The Monte Carlo method was preformed to simulate the nonlinear responses of the photoluminescence intensity under different external electric fields. The results show that the range in which luminescence quenching is linearly proportion to THzfield could be over 60kV/cm. On the basis of the result, a novel principle for THz modulation and coherent detection was proposed. This study was the fundamental for the development and application of THz detection devices and high speed electronic devices.It’s published in Optics Letters, Vol. 37, No. 9, P. 1433-1435(2012).
This work is supported by the National Natural Science Foundation of China under grant No. 10974063 and 61177095, Hubei Natural Science Foundation under grant No. 2010CDA001,Ph.D. Programs Foundation of Ministry of Education of China under grant No. 20100142110042, and the Fundamental Research Funds for the Central Universities, HUST: 2010MS041 and 2011TS001.
Fig. 1 (a) and (b) are transient density of electrons and holes respectively as a function of delay times Δt1 and Δt2. The dash black line in (c) is the THz field and the red line is PL intensity as a function of delay time Δt1. (d) is the PL intensity as a function frequency.