Design Analysis and Performance Optimization of a Lyot Filter for Semiconductor Optical Amplifier Pattern Effect Suppression

Comparison of Basic Notch Filters for Semiconductor Optical Amplifier Pattern Effect Mitigation

“…Similarly, the calculated MRR radius complies with the permissible range of values specified for this parameter from the study in [33]. Furthermore, ∆τ and R are such that the filtered-out data pulses retain their initial shape, as addressed in [15,29] and verified again below. Having determined the FSR of the ODI and MRR, the next step is to do the same for their detuning.…”

“…Equations (3.11)-(3.12) and (B.9)), whose round-trip delay is T R = 2πn e f f R/c, while the right-hand side represents the same quantity for the ODI [15]. Letting then r = l = 0.95, so as to ensure that the condition of critical coupling for the MRR is favorably met, but also to preserve the continuity with previous relevant work [33], leads to:…”

“…In order to allow conventional SOAs to fulfil their classical role, it is necessary to combat the PE and its deleterious consequences. For RZ pulses, this requires lowering their power well below the SOA strong saturation regime, as well as substantially shortening their width [15]. These actions are not sufficient since the first one results in a poor optical signal-to-noise ratio (OSNR), reduced maximum output power, closer amplifier spacings and narrower input power dynamic range (IPDR) [16], while the second one requires applying intricate ultrafast pulse generation approaches [17] and dealing with practical related issues, such as nonlinear effects [18] and intraband phenomena [19].…”

“…Among the various methods that have been proposed to improve the pattern-dependent performance of SOAs used for direct signal amplification (see [15] and the relevant references therein), optical filtering has attracted intense research interest [20][21][22][23][24][25]. This passive method has been conceived of based on the observation that pulse amplification in an SOA is accompanied by spectral broadening to longer wavelengths (red shift) due to the manifestation of self-phase modulation (SPM) [26].…”

“…During last few years, we have applied the optical filtering technique for SOA pattern effect suppression by means of a platform comprised of different notch filters [15,[28][29][30][31][32][33]. Among these filters, we particularly distinguish the optical delay interferometer (ODI) [30][31][32] and the microring resonator (MRR) [33], which share several common features, such as an all-optical and passive nature, simple structure, compatibility both with fiber medium and microelectronic fabrication processes, compact size, periodic and tunable transfer function and potential for integration and co-packaging with the SOA in a single module.…”