  Squeezed states are a versatile class of quantum states with applications
ranging from quantum computing to high-precision detection. We propose a method
for generating tunable squeezed states of light with multiple modes encoded in
frequency bins. Our method uses custom-engineered spontaneous parametric
downconversion pumped by a pulse-shaped pump field. The multi-mode squeezed
states are generated in a single pass and can be tuned in real time by
adjusting the properties of the pump field. Exploring new quantum states of
light, encoded in new degrees of freedom, can be a fruitful path toward
discovering new quantum applications.
