Resonant cavity enhanced photodetectors (RCE-PDs): structure, material, analysis and optimization

Abstract

Resonant cavity enhanced photodetectors (RCE-PDs) are promising candidates for applications in high-speed optical communications and interconnections. In these high-speed photodetectors, both high bandwidth and high external quantum efficiency can be achieved simultaneously because of the multipaths of the incident light due to the presence of the FabryPérot cavity into which the photodetector is inserted. In this paper, state-of-the-art RCE-PDs are discussed. Different structures of the RCE-PDs such as RCE-PIN, RCE-APD, and RCE-MSM PDs are presented and discussed. The material requirements for the RCE PDs with different material system compositions for the different structures and different wavelengths of the incident light that the photodetectors are sensitive to, are discussed. An overview of the analysis and a SPICE model of the RCE-PDs will be presented. These analyses include the calculations of quantum efficiency (QE), impulse response and frequency response of RCE-PDs. These analyses are sensitive to the standing wave effect (SWE) and to carrier diffusion, and both effects are studied. Optimization procedures for the design of ultrafast RCE-PDs will be presented, showing how the QE, bandwidth and speed of these photodetectors can be improved by adjusting the parameters of both the cavity and the photodetector itself. Finally, comparisons to experimental results and a survey of the performance of state-ofthe-art of RCE-PDs will be presented.

III-Nitrides Resonant Cavity Photodetector Devices

“…Taking this into account, the quantum efficiency of the RCE PD is a periodic function of λ and reaches the maximum values at resonance wavelengths, defined by [ 23 ] where R 1 and R 2 are the reflectivity of the top and bottom mirrors, respectively, α is the absorption coefficient of the active layer and d , its thickness. For a thin active layer, , and hence η max becomes as follows [ 23 ]: …”

Novel resonant cavity-enhanced absorber structures for high-efficiency midinfrared photodetector application

“…This simple model has nevertheless a prevalent use for initial designs, 4 and can be further refined by joint electronic-device simulations. 4,5,9 In this study, the emphasis is placed on optimizing the peak absorbance and fulfillment of the resonant condition indicated by Eq. (1) at a center-MWIR design wavelength of λ 0 = 4.415 μm, which is kept fixed throughout this paper.…”

“…The subject of optical properties of multilayers is widely documented. [1][2][3] Over the past two decades, the science and technology of diverse resonant-cavity-enhanced (RCE) photonic devices, such as RCE photodetectors (PDs), 4,5 have steadily matured. Highefficiency PDs are an essential component in optical communication systems, optical interconnects and information processing, and in metrology and sensing.…”

New resonant cavity-enhanced absorber structures for mid-infrared detector applications

“…Optical communication, interconnection and information processing systems require high-efficiency photodetectors (PDs). In response to this demand, the field of resonant-cavity-enhanced (RCE) PDs has steadily maturated over past two decades [3,4]. For thermal PDs, the optical absorbance A is an accurate measure of the efficiency, while for photodiodes and photo-conductors the key figure is the quantum efficiency η.…”

“…For thermal PDs, the optical absorbance A is an accurate measure of the efficiency, while for photodiodes and photo-conductors the key figure is the quantum efficiency η. For initial design of the RCE PDs, the adoption of η ≈ A has a widespread use [3,4] since thus the analysis is framed into optics alone rather than being restricted to a specific PD technology. It appears [3] that for obtaining η ≈ 100% it is at least necessary to have ∼ 100% resonant reflectivity from the front mirror, which is problematic for a DBR of any practical thickness because of the tight material requirements for epitaxial growth.…”