Operation of a Bloch oscillator
نویسندگان
چکیده
We report the operation of a Bloch oscillator. The active medium was a staticvoltage driven, doped GaAs/AlAs superlattice which was electromagnetically coupled to a resonator. The oscillator produced tuneable microwave radiation (frequency ~ 60 GHz; power ~ 0.5 mW; efficiency ~ 4 %). The gain (~ 10 cm) was due to the nonlinearity mediated by miniband electrons. We also present a theory of the oscillator. The Bloch oscillator should in principle be feasible for generation of radiation up to frequencies of 10 THz and more.
منابع مشابه
Bloch gain in dc-ac-driven semiconductor superlattices in the absence of electric domains
We theoretically study the feasibility of amplification and generation of terahertz radiation in dc-ac-driven semiconductor superlattices in the absence of electric domains. We find that if in addition to a dc bias a strong terahertz pump field is applied, a Bloch gain profile for a small terahertz signal can be achieved under the conditions of a positive static differential conductivity. Here,...
متن کاملMultiphoton Bloch-Siegert shifts and level-splittings in spin-one systems
Abstract. We consider a spin-boson model in which a spin 1 system is coupled to an oscillator. A unitary transformation is applied which allows a separation of terms responsible for the Bloch-Siegert shift, and terms responsible for the level splittings at anticrossings associated with Bloch-Siegert resonances. When the oscillator is highly excited, the system can maintain resonance for sequent...
متن کاملLarge-amplitude oscillation dynamics and domain suppression in a superlattice Bloch oscillator
We analyze the current dynamics of a superlattice Bloch oscillator under conditions where, in addition to the dc bias field causing a negative differential ac conductivity, a similarly strong ac field is present, at a frequency somewhat below the Bloch frequency associated with the dc field. The differential conductivity at the ac drive frequency is then negative, but, because of the strong non...
متن کاملA Phase Noise Reduction Technique in LC Cross-coupled Oscillators with Adjusting Transistors Operating Regions
In this paper, an intuitive analysis of a phase noise reduction technique is done, and then a modified structure is proposed to achieve higher phase noise reduction than the original one. This method reduces the impact of noise sources on the phase noise by decreasing closed-loop gain in zero-crossings points and moving this high closed-loop gain to the non-zero-crossings points. This reduction...
متن کاملInterband optical investigation of Bloch oscillations in semiconductor superlattices
The experimental observation of Bloch oscillations in solids was long thought to be out of experimental reach. The invention of the semiconductor superlattice has changed this situation decisively. Transport experiments performed in the past two decades have given indirect evidence for the existence of Bloch oscillations. Recently, it has been possible to directly observe Bloch oscillations in ...
متن کامل