With no explanation, label text_A→text_B with either "not_related" or "related".
text_A: There is a film called Toy Story.
text_B: An optical parametric oscillator -LRB- OPO -RRB- is a parametric oscillator that oscillates at optical frequencies .. parametric oscillator. parametric oscillator. It converts an input laser wave -LRB- called `` pump '' -RRB- with frequency into two output waves of lower frequency by means of second-order nonlinear optical interaction .. laser. laser. order. Orders of approximation. nonlinear optical interaction. nonlinear optics. The sum of the output waves ' frequencies is equal to the input wave frequency  : .. For historical reasons , the two output waves are called `` signal '' and `` idler '' , where the output wave with higher frequency is called signal .. A special case is the degenerate OPO , when the output frequency is one-half the pump frequency , , which can result in half-harmonic generation when signal and idler have the same polarization .. half-harmonic generation. half-harmonic generation. The first optical parametric oscillator was demonstrated by Joseph Giordmaine and Bob Miller in 1965 , five years after the invention of the laser , at Bell Labs .. parametric oscillator. parametric oscillator. laser. laser. Optical parametric oscillators are used as coherent light sources for various scientific purposes , and to generate squeezed light for quantum mechanics research .. squeezed light. squeezed light. A Soviet report was also published in 1965 .
not_related.