Stable and Reduced-Linewidth Laser Through Active Cancellation of Reflections Without a Magneto-Optic Isolator

Non-Magneto-Optic Waveguide Isolator

We report on a novel technique to realize a waveguide optical isolator without using conventional magneto-optical materials and external magnets. The simulations are repeatedly performed using Beam Propagation Method (BPM) to confirm the accuracy. The simulation results show that the forward and backward propagations reach 2.54 and 15.68 dB, respectively.

Magneto-optic Laser Beam Steering

Active linewidth-narrowing of a mid-infrared quantum cascade laser without optical reference.

We report on a technique for frequency noise reduction and linewidth-narrowing of a distributed-feedback mid-IR quantum cascade laser (QCL) that does not involve any optical frequency reference. The voltage fluctuations across the QCL are sensed, amplified and fed back to the temperature of the QCL at a fast rate using a near-IR laser illuminating the top of the QCL chip. A locking bandwidth of...

A Unidirectional Er3+-Doped Fiber Ring Laser without Isolator

An Er"+-doped fiber ring laser with unidirectional operation without optical isolator has been investigated for different cavity conditions. The fiber ring laser cavity is built in such a way that the optical fields propagating in the two directions suffer different losses. As a consequence, the laser oscillation appears in a quasi-unidirectional form. By incorporating a fiber pigtailed bandpas...

the effect of lexical and grammatical collocation instruction through input flooding versus awareness raising on short-term and delayed retention as well a active use

this study attempted to explore if teaching english collocations through two different modes of awareness-raising and input flooding has any possible differential effect on immediate retention as well as retention in a delayed assessment. it also compared the possible differential effect of teaching english collocations implicitly and explicitly on actively using the items in writing. m...