Tuning range extension by active mode-locking of external cavity laser including a linearly chirped fiber bragg grating

Broad-band laser emission and optical mode-locking of a Fabry-Perot laser formed between two Linearly Chirped Fiber Bragg Gratings

“…After exiting the cavity, the emitted light is measured by an Optical Spectral Analyzer (OSA). Taking into account the oscillation condition shown as follows, n fb L lf + n eff L(λ) + n a L a + n fb L rg + n eff L(λ) = k λ/ 2 ( 1 ) where k is the mode number, and considering n eff L(λ) small enough to be neglected at the left side of the equation. The reflection bandwidth of the gratings is also straightforward, as the minimum reflected wavelength (λ 0 ) corresponds to the first Bragg period and the maximum reflected wavelength (λ e ) to the last Bragg period.…”

“…According to the oscillation equation 1 , the following expression shows the grating chirp as a function of the cavity length for this laser structure,…”

“…Another property of this type of grating is that each wavelength in the reflection band has its own effective reflective plane. Using this particularity to vary the effective optical length of oscillation in function of wavelength, one of the mirrors of a Fabry-Perot cavity has been replaced by Bergonzo et al 1 …”

Design of Bragg gratings having negative group time delay for continuum generation

“…Starting from the concept of Continuum cavity developed by Bergonzo et al 1 for the case of wide tuning range lasers, this paper will try to extend the same principle for the case of the widening of resonant modes of a Fabry-Perot cavity. The basic structure is shown in Fig.…”

Wavelength-tunable 10 GHz actively harmonic mode-locked fiber laser based on semiconductor optical amplifier

“…In general, the wavelength-selective elements will have a limited tuning range or gain bandwidth that restricts the tunability of the pulsed source [21]. To define the output wavelength, the wavelength-tunable SOA-based laser usually contains a wavelength-selective element [22][23][24], and most of the published works have tuning ranges of about 30-50 nm [25]. In [21], an intra-cavity birefringence loop mirror filter (LMF) is used to define the output wavelength across a range of 97 nm, but it is difficult to adjust accurately the polarization controller (PC) inside the LMF.…”