Single-Shot CEP Change Detection in a Nanoantenna Network

John Fleming demonstrated in 1905 the first vacuum diode based on thermionic electron emission for the rectification of AC electric fields and started an avalanche of developments in microwave electronics such as sensitive wireless receivers or signal amplifiers [1]. Around 100 years later, lasers connected the optical domain with the microwave domain by coherently locking optical frequencies to microwave frequencies with carrier-envelope (CE) offset stable frequency combs, enabling many applications such as precision metrology [2]. To directly drive electronic systems with optical frequencies, many approaches based on carrier-envelope phase (CEP) stable few-cycle NIR pulses, directly driving sub-cycle electron currents at optical frequencies in dielectrics, metal-vacuum-metal junctions, or gases have been investigated [3]–[6]. We present an approach based on the large-scale integration of metallic nanoantennas into conventional electronic readout circuitry; see Figs. 1 a and b. When irradiating an array of $\sim 1000$ antennae with 18 fs, CE-stable pulses having a center wavelength of 2640 nm, repetition rate of 50 kHz, and peak field strengths up to 1.7 Vnm ⁻¹ , we observe shot-to-shot changes in CE phase dependent charge amplitudes up to $\sim 3000 \ \mathrm{e}$ , see Fig. 1 c. We further investigated the CE sensitive charge amplitude as a function of field strength and found excellent agreement with models based on the quasi-static tunneling approximation extracting an effective field enhancement of 8 by the antenna structure, in very good agreement with our electromagnetic simulation; see Fig. 1 d.