Abstract

We performed intramodal scalar optical injection using fibered highly monomode (30 dB) DFB multiquantum well semiconductor laser (@ 1550 nm). We applied a microwave current modulation at a subharmonic frequency (f_m = 5 GHz) of the optical detuning (3f_m) to an injected but frequency unlocked slave (i.e. containing two distinct components in its Fabry-Perot spectrum (fig. 1)). This technique has previously been used to generate optical millimeter waves at k.f_m ^1,2. A change (increasing and/or narrowing) of the precise 3f_m peak with respect to the surrounding beat note corresponding to the two components in the unmodulated FP spectrum can be observed. The purity of this 3f_m component is known to be that of the microwave generator which can be subhertzian and is resolution limited by the resolution bandwidth of our electrical spectrum analyzer (10 kHz).

© 1998 IEEE