No abstract

Electro-optic time lenses are promising experimental components for photonic spectral-temporal processing of quantum information. We report a stable method to realize an electro-optic time lens, which relies on the amplification of an electronic response of a fast photodiode. The method does not require a repetitive clock and may be applied to aperiodic optical signals. We experimentally demonstrate the approach using single-photon pulses, and directly verify its aperiodicity. The approach will enable the construction of complex electro-optic temporal optical systems.

Manipulation of quantum optical pulses, such as single photons or entangled photon pairs, enables numerous applications, from quantum communications and networking to enhanced sensing. Common methods to shape laser pulses based upon filtering or amplification cannot be employed with quantum light pulses as these approaches introduce detrimental loss and noise to the system. Here, methods to control and measure quantum light pulses based upon deterministic application of targeted phases in time and frequency domains are reviewed, along with recent demonstrations of quantum applications.

The power spectrum of an optical field can be acquired without a spectrally resolving detector by means of Fourier-transform spectrometry, based on measuring the temporal autocorrelation of the optical field. Analogously, we here perform temporal envelope measurements of ultrashort optical pulses without time resolved detection. We introduce the technique of Fourier transform chronometry, where the temporal envelope is acquired by measuring the frequency autocorrelation of the optical field in a linear interferometer. We apply our technique, which is the time-frequency conjugate measurement to Fourier-transform spectrometry, to experimentally measure the pulse envelope of classical and single photon light pulses.

We experimentally show spectral bandwidth compression of broadband heralded single photons by two orders of magnitude, from 1.5 nm to 5 pm, increasing a photon flux through a 2 pm filter by a factor of 12.