Fiber loop reflectors

Abstract

The theory and application of fiber loop reflectors, fabricated by forming a fiber loop between the output ports of a directional coupler, is described. The reflectivity of the loop is shown to depend upon the coupling characteristics of the coupler and on the degree of birefringence in the fiber loop. Measured loop. reflectivities, in terms of wavelength response, coupling ratio, and loop birefringence are shown to agree very well with theory. Two applications of the fiber reflector are briefly discussed; an all fiber laser and a duplex optical communications link using a single light source.

A broadband ytterbium-doped tunable fiber laser for 3He optical pumping at 1083�nm

“…2 displays the architecture of a fiber oscillator in which a loop mirror is used to close the FP linear cavity. Fiber loop reflectors are easily fabricated and exhibit large reflectivities (50-75%) over a broad frequency range [35]. The selective tunable FBG is spliced at the output end of the cavity.…”

“…4, solid dots) mainly arises from the fact that two measurements were not performed in the same frequency range. Indeed, over the 200 GHz broad tuning range, the operating conditions of the laser cavity vary due to changes in the loop mirror reflectivity [35]. The influence of the mirror characteristics on the laser FWHM is analyzed and discussed in more detail in [30,31].…”

Functional quantum computing: An optical approach

“…In the absence of a control pulse, a NOLM can be aligned so as to perfectly reflect all incoming signal pulses. This perfect reflection is a result of destructive interference between the clockwise and counter-clockwise paths of the Sagnac loop [25]. A dual-wavelength control pulse is multiplexed in and out of the clockwise path of the Sagnac loop and consists of two equal-energy cross-polarized optical pulses such that a signal in the clockwise path of the Sagnac loop receives a polarization-independent π phase shift [26].…”

Optical characteristics of transparent PMNT ceramic and its application at high speed electro-optic switch

“…Assuming θ is an angle to one principal axis of the PMNT sample for the clockwise wave, then the orientation for counterclockwise wave is π−θ or −θ due to the 180°direction change induced by the loop structure. The corresponding phase retarder matrixes for CW and CCW waves are expressed as [14][15][16]: reflection power I 1 and transmission power I 2 of the Sagnac Interferometer by the matrix calculation as follows:…”