Symmetric photodetector integrated with multilayer dielectric resonator cavity for 400 Gb/s optical communication system

Advances in High–Speed, High–Power Photodiodes: From Fundamentals to Applications

“…Based on the reflection theory of RCE, many kinds of reflected mirror models, as shown in Figure 19b-f, which are used in vertical-mesa and waveguide types of PDs to improve the responsivity without sacrificing the bandwidth, have been proposed in the last 30 years. Most of the fabrication of reflected mirrors are the material combinations of DBRs (Figure 19b) [154][155][156][157][158][159][160][161][162][163][164][165], while periodic (or non-periodic) strip or concentric circular subwavelength gratings (SWGs), two-dimensional square bulk SWGs (Figure 19c) [140,161,[166][167][168][169][170][171][172][173][174], Au mirrors [149], and even the scattering structure formed by a periodic cylindrical particle array [175], also can be employed as reflected ones. Those types of mirrors are usually either on the PD bottom (i.e., bottom mirrors) realized by direct epitaxial growth by metal-organic chemical vapor Deposition (MOCVD) or quasimonolithically integrated using micron-level-thick benzocyclobutene (BCB) bonding (or integrated [69]) techniques, or on the top of the PD (i.e., top mirrors) implemented by employing the metal contacts (or strip gratings) by magnetic sputtering (or electron beam evaporation) or the flip-chip method with chemical etching [158,[176][177][178].…”

“…Based on the reflection theory of RCE, many kinds of reflected mirror models, as shown in Figure 19b-f, which are used in vertical-mesa and waveguide types of PDs to improve the responsivity without sacrificing the bandwidth, have been proposed in the last 30 years. Most of the fabrication of reflected mirrors are the material combinations of DBRs (Figure 19b) [154][155][156][157][158][159][160][161][162][163][164][165], while periodic (or non-periodic) strip or concentric circular subwavelength gratings (SWGs), two-dimensional square bulk SWGs (Figure 19c) [140,161,[166][167][168][169][170][171][172][173][174], Au mirrors [149], and even the scattering structure formed by a periodic cylindrical particle array [175], also can be employed as reflected ones. Those types of mirrors are usually either on the PD bottom (i.e.…”