Time lenses are tool recently developed in ultrashort optical pulse physics
that explore the analogy between temporal phase modulation and chromatic
dispersion in time with spatial phase modulation and free propagation in
space, allowing to compress ultrashort optical pulses. Here we extend and
experimentally demonstrate this idea to manipulate much more narrow-band
single photon states, which can be resonant with microscopic systems like
atoms, molecules, color centers, and quantum dots. This idea provides a
powerful building block for quantum interfaces, 
connecting a wide spectrum of physics disciplines for implementing
heterogenous hybrid quantum networks.