Modulation instability of broad optical beams in unbiased photorefractive pyroelectric crystals

Highlights: • Modulation Instability in pyroelectric photorefractives is investigated. • Space charge field considered due to pyroelectric effect only. • External electric field replaced by pyroelectric field with clear advantages. • MI gain depends upon incident intensity and magnitude of temperature change. - Abstract: We present a study of the one dimensional modulation instability due to a broad optical beam in pyroelectric photorefractive crystals where the space charge field is formed due to solely the pyrolectric effect. The one-dimensional growth rate of the modulation instability depends upon the intensity of the incident beam and the magnitude of the temperature change. Relevant example of a Strontium Barium Niobate crystal is taken to illustrate the theoretical analysis.