Elastic strings make up the electric fields and magnetic fields surrounding a photon. According to elastic string theory, the negative electric field is composed of e-electons and the positive electric field is composed of p-electons. The magnetic fields are composed of n-magnons and s-magnons.
During the first half of the oscillation cycle, the photon is creating p-electons and s-magnons, and in the second half of the oscillation cycle, it is creating e-electons and n-magnons. This is shown in the next diagram:

Notice these fields are not being cancelled out by their complementary counterpart; i.e., p-electons are not being cancelled by e-electons on the same photon. The same applies to the magnons created. Notice too how the fields are directed at a 90 degree angles from the flight path of the photon, and at 90 degree angles from each other.
By convention, one oscillation period goes from the apex of one p-electon field to the apex of the next p-electon field, but one oscillation cycle is composed of two distinct string cycles. Shortly after the apex of the first p-electon field, there is a brief period of time when the photon is not making any elastic strings (X1), and immediately following the creation of the e-electon field, there is another period when it is quiescent (X2).
It is convenient to think of a string cycle beginning at a point when the photon is not making any strings. Shortly thereafter, it begins ejecting strings until there are a maximum number, and then the strings retract back to their source. In one string cycle p-electons and s-magnons are created then retracted, and in the next string cycle, e-electons and n-magnons are created then retracted. These two events make up one oscillation period.
It is possible that at the time the photon is creating p-electons it may be creating n-magnons rather than s-magnons, etc. If someone knows the proper sequence, I would appreciate hearing from you.