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Yes - but not really.

A single photon has a single value for it's related wavelength - so it's perfectly monochromatic, in a formal sense.

But, in a physical sense, the concept of a spectrum (like: monochromatic) basically does not apply to a single photon.

In practice, you do not have these "single photons, with some specific wavelength" to actively work with, as implied in the question - that would mean to ignore Heisenberg.
But you may measure you had one - even with a specific wavelength.

See also
Frequency and wavelength of photons
and
Can a photon exhibit multiple frequencies?
discussing that a photon may be a superposition of multiple frequency states - before measuring, of course.

Yes - but not really.

A single photon has a single value for it's related wavelength - so it's perfectly monochromatic, in a formal sense.

But, in a physical sense, the concept of a spectrum (like: monochromatic) basically does not apply to a single photon.

In practice, you do not have these "single photons, with some specific wavelength" to actively work with, as implied in the question - that would mean to ignore Heisenberg.
But you may measure you had one - even with a specific wavelength.

See also
Frequency and wavelength of photons
and
Can a photon exhibit multiple frequencies?
discussing that a photon may be a superposition of multiple frequency states - before measuring, of course.

Yes - but not really.

A single photon has a single value for it's related wavelength - so it's perfectly monochromatic, in a formal sense.

But, in a physical sense, the concept of a spectrum (like: monochromatic) basically does not apply to a single photon.

In practice, you do not have these "single photons, with some specific wavelength" to actively work with, as implied in the question - that would mean to ignore Heisenberg.
But you may measure you had one - even with a specific wavelength.

See also  Frequency and wavelength of photons

Yes - but not really.

A single photon has a single value for it's related wavelength - so it's perfectly monochromatic, in a formal sense.

But, in a physical sense, the concept of a spectrum (like: monochromatic) basically does not apply to a single photon.

In practice, you do not have these "single photons, with some specific wavelength" to actively work with, as implied in the question - that would mean to ignore Heisenberg.
But you may measure you had one - even with a specific wavelength.

See also 
Frequency and wavelength of photons
and
Can a photon exhibit multiple frequencies?
discussing that a photon may be a superposition of multiple frequency states - before measuring, of course.

Yes - but not really.

A single photon has a single value for it's related wavelength - so it's perfectly monochromatic, in a formal sense.

But, in a physical sense, the concept of a spectrum (like: monochromatic) basically does not apply to a single photon.

In practice, you do not have these "single photons, with some specific wavelength" - that would mean to ignore Heisenberg.

See also Frequency and wavelength of photons

Yes - but not really.

A single photon has a single value for it's related wavelength - so it's perfectly monochromatic, in a formal sense.

But, in a physical sense, the concept of a spectrum (like: monochromatic) basically does not apply to a single photon.

In practice, you do not have these "single photons, with some specific wavelength" to actively work with, as implied in the question - that would mean to ignore Heisenberg.
But you may measure you had one - even with a specific wavelength.

See also Frequency and wavelength of photons