Conservation of energy during generation of entanglement

Understanding conservation of energy during generation of entanglement.

In the experiment for generation of entangled pair of photons via SPDC

Single photons are struck on a BBO crystal.

In about 1 in a trillion of such collisions, two photons emerge.

Questions:

1. Is the combined energy of the two photons exactly equal to the "pump/original" photon?

2. If a photon is the smallest quanta of energy, then how do we explain the fact that its energy has been split among two photons?

or

3. Are there two parts to the energy of a photon? i.e.

a) energy of the photon. i.e. photon as a moving ball of energy.

taking the example of a ball --> the ball can be converted to energy

b) energy on the photon. i.e. momentum of the photon

taking the example of a ball --> the ball is moving at a certain velocity it caries some force/energy/momentum

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1. Each photon is half the frequency and therefore half the energy of the down converted photon.

2. A photon is not the smallest quanta of energy. Energy is proportional to frequency.

tom.stoer
2. there is no smallest energy quantum and no energy quantization in general; for frequency f → 0 you have for energy E = hf → 0; so a photon is the smallest quantum of energy for a fixed frequency

3. no, you can't split energy in that way; it makes no sense

2. there is no smallest energy quantum and no energy quantization in general; for frequency f → 0 you have for energy E = hf → 0; so a photon is the smallest quantum of energy for a fixed frequency

3. no, you can't split energy in that way; it makes no sense