Squeezing of photon-number fluctuations in the frequency range wider than 300 MHz in light-emitting diodes at room temperature

We present the experimental results on the squeezing of photon-number fluctuations in tailor-made light-emitting diodes (LED’s). In the LED, a highly p-doped separate confinement heterostructure is adopted as the active region to shorten the radiative recombination lifetime. In addition, a photodiode is monolithically integrated with the LED to enhance the photon-collection efficiency, which allows strong squeezing. The squeezing below the standard quantum-limit level over a wide frequency range, near-dc to 300 MHz, at room temperature and the maximum squeezing depths, 0.86 dB at room temperature and 2.6 dB at low temperature, are demonstrated.