Near threshold all-optical backaction amplifier

Abstract

A near threshold all-optical backaction amplifier is realized. Operating near threshold in an integrated micronscale architecture allows a nearly three orders of magnitude improvement in both gain and optical power requirements over the only previous all-optical implementation, with 37 dB of gain achieved for only 12 µW of input power. Minor adjustments to parameters allows optical filtering with narrow bandwidth dictated by the mechanical quality factor. Operation at cryogenic temperatures may enable standard quantum limit surpassing measurements and ponderomotive squeezing.Optical amplifiers are ubiquitous in present-day communications and sensing technologies, and are fundamental to many high precision scientific endeavors. The classic example is the erbium doped fiber amplifier (EDFA) which, with pump power and gain of around 100 mW and 20 dB respectively[1], dramatically reduces power consumption and speeds up performance in long-haul fiber optic communications, enabling modern optical telecommunications networks. It is well known that phase sensitive amplifiers based on the optical parametric nonlinearity offer the means to both further reduce pump power, with nonlinear thresholds at the level of microwatts [2,3], and boost noise performance past the 3 dB quantum limited noise figure of phase insensitive amplifiers [4]. This letter reports an on-chip all-optical phase sensitive amplifier where, in contrast, the nonlinearity arises, not from an intrinsic optical nonlinearity, but rather from the radiation pressure driven dynamical interplay between the optical and mechanical structure of a microcavity optomechanical system. Such backaction amplifiers [5] are but one example of the rapid progress currently occurring in the emergent field of cavity optomechanics based on the dynamical backaction between light and matter; with recent demonstrations of mechanical cooling[6-8], optomechanical induced transparency (OMIT) [9], regenerative mechanical oscillation [6,10,11], optomechanical induced chaotic oscillation [12], tunable phonon lasers [13] and even technological applications such as a photonic radio frequency (RF) down converter [14].The first demonstration of backaction amplification, and only previous all-optical demonstration, used an electronically locked Fabry-Perot cavity with milligram effective mass [5]. However, due to the close proximity of parametric instability, operation was precluded near the threshold for optomechanical parametric oscillation where the amplification is strongly enhanced. This limited the gain achieved to 8 dB, with 10 mW of input optical power. Here, by contrast, the optomechanical resonator is an integrated monolithic silica microtoroid [15] with microgram effective mass, high mechanical stability, and ultrahigh optical quality factor. Critically, the thermal bistability [16] of silica provides strong thermo-optic locking to the blue detuned side of optical resonance [17,18]. This allowed operation close to parametric instability, resulting in

Noiseless Quantum Measurement and Squeezing of Microwave Fields Utilizing Mechanical Vibrations

“…Therefore, these amplifiers are currently actively used in quantum science. Also electromechanical systems have been investigated to this end [11][12][13][14][15]. In recent work, Refs.…”

Low-Noise Amplification and Frequency Conversion with a Multiport Microwave Optomechanical Device

“…This limit has been approached with Josephson parametric amplifiers [9][10][11][12][13][14], however, such amplifiers are limited to relatively weak input signals. Optomechanical amplifiers or detectors, utilizing the interaction between electromagnetic waves and a mechanical resonator inside a cavity [15], have been demonstrated in the microwave and optical regime [16][17][18][19], but existing techniques suffer from a limited gain and bandwidth as well as noise levels well above the SQL.…”

“…As we show theoretically, our scheme can reach the SQL for both of these processes. Unlike existing optomechanical amplifiers [16,17], the bandwidth of amplification in our scheme can be increased up to the cavity linewidth, and the product of gain and bandwidth has no fundamental limit. Remarkably, we show in experiment that the quantum limit can be closely approached even at a high temperature where the mode occupation numbers 1, which allows for an interpretion in terms of reservoir engineering [20,[24][25][26][27].…”

Optomechanically induced transparency in a membrane-in-the-middle setup at room temperature

“…In such a case, the probe beam constructively interferes with the Stokes sideband of the pump beam which is resonant with the cavity, and may be amplified in transmission within a very narrow frequency window. This is the optomechanical analogue of electromagnetically induced amplification [9,19], demonstrated in the unresolved sideband limit in [27][28][29], and closely related to the electromagnetically induced absorption observed in atomic gases [30]. The latter consists in the decrease of the total power at the output of the medium for increasing pump power, and may occur only when the medium internal losses are larger than the external losses.…”