Subnoise Detection and Passive Amplification of Frequency Combs through Customized Coherent Spectral Energy Redistribution

Arbitrary Energy‐Preserving Control of Optical Pulse Trains and Frequency Combs through Generalized Talbot Effects

“…In particular, an important set of these techniques is based on the theory of Talbot self‐imaging . Such methods have been developed to achieve multiplication and/or division of the repetition period of pulse trains by arbitrary (integer or fractional) factors, as well as arbitrary control of the FSR of frequency combs .…”

“…In particular, an important set of these techniques is based on the theory of Talbot self‐imaging . Such methods have been developed to achieve multiplication and/or division of the repetition period of pulse trains by arbitrary (integer or fractional) factors, as well as arbitrary control of the FSR of frequency combs . Furthermore, due to the inherent phase‐only nature of these approaches, the entire energy of the processed signal is ideally preserved; as a result, these methods are able to reduce the impact of noise and signal aperiodicities (such as timing jitter and pulse‐to‐pulse intensity fluctuations) under certain operation conditions .…”

“…Similarly to the temporal case, the methodology outlined here allows for arbitrary control of the FSR of a frequency comb, where the pulse period of its temporal train representation is related to the achieved FSR (the obtained pulse period is the exact inverse of the obtained FSR). FSR control techniques proposed to date based on this methodology only deal with spectral period control; consequently, they end with step 3 (Figure (b.3)) for fractional FSR multiplication/division, or step 2 (Figure (b.2)) for integer FSR multiplication (see Section ) . Step 4 (TPM, Figure (b.4)) is only necessary if one wishes to obtain an output frequency comb free of line‐to‐line phase variations and/or to control the temporal pulse period accordingly.…”

“…Conservation of energy ensures that the output comb lines have times the energy of the individual input lines. This energy redistribution only affects the coherent components of the input signal that satisfy the designed Talbot conditions, leading to an effect of noiseless spectral amplification of the individual output comb lines when …”

“…A distinctive feature of temporal and spectral Talbot effects is that they enable manipulation of the repetition rate of an incoming pulse train or the FSR of its corresponding frequency comb spectrum without altering the individual temporal pulse characteristics (i.e., the pulse's complex temporal envelope, including shape and duration) and the spectral envelope of the corresponding frequency comb. Moreover, techniques based on such methodology have been proposed to manipulate the repetition period of pulse trains and frequency combs at will, not limited to integer division . As illustrated in Figure b, these methods involve specific combinations of SPF and TPM operations corresponding to concatenated individual realizations of temporal and spectral Talbot effects.…”