  The interaction of metal-molecule-metal junctions with light is considered
within a simple generic model. We show, for the first time, that light induced
current in unbiased junctions can take place when the bridging molecule is
characterized by a strong charge-transfer transition. The same model shows
current induced light emission under potential bias that exceeds the molecular
excitation energy. Results based on realistic estimates of molecular-lead
coupling and molecule-radiation field interaction suggest that both effects
should be observable.
