A new technique and a physical model for writing extremely short length Bragg gratings in optical fibers have been developed. The model describes the effects of diffraction on the spatial spectra and therefore, the wavelength spectra of the Bragg gratings. Using an interferometric technique and a variable aperture, short gratings of various lengths and center wavelengths were written in optical...

A new technique has been developed for sensing both temperature and strain simultaneously by using dual-wavelength fiber-optic Bragg gratings. Two Bragg gratings with different wavelengths were inscribed at the same location in an optical fiber to form a sensor. By measuring the wavelength shifts that resulted from the fiber being subjected to different temperatures and strains, the wavelength-...

An approach for creating two-dimensional arrays of coherently coupled vertically emitting laser cavities is demonstrated. This is achieved by creating a 232 array of defect cavities within the top distributed Bragg reflector of a photonic crystal vertical cavity surface-emitting laser. The optical coupling occurs laterally through coupling regions defined between the defect cavities. Modifying ...

We present a new class of dynamic coherence protocols, called Dynamic Boundary-Restricted (DBR) coherence protocol class, for DSM systems in error-prone networks whose instances ooer highly available access to DSM data at low operation costs. The approach is based on the Boundary-Restricted (BR) coherence protocol class. Our analysis provides the overall cost savings by using a DBR coherence pr...

We demonstrate an amplitude-based bending/displacement sensor that uses a plastic photonic bandgap Bragg fiber with one end coated with a silver layer. The reflection intensity of the Bragg fiber is characterized in response to different displacements (or bending curvatures). We note that the Bragg reflector of the fiber acts as an efficient mode stripper for the wavelengths near the edge of th...

This paper presents the switched-beam slot antenna over the electromagnetic band-gap (EBG) reflector. This antenna is composed of two slot elements fed with phase difference and the EBG reflector, which is applied in order to realize the low profile structure. The radiation characteristics of this antenna are calculated using the FDTD method. The calculated results show that the antenna height ...

We present a multi-active-region bipolar-cascade distributed-Bragg reflector (DBR) laser emitting around 910 nm. The three active regions and two tunnel junctions are located in single waveguide core sharing the same third-order vertical mode. A slope efficiency of 2.25 W/A was measured with threshold current density 400 A/cm2. Due to implemented 7th Bragg order surface grating, exhibits narrow...

This article discusses possible solutions to limitations in light extraction efficiency of light-emitting diodes (LEDs) using new types of triple-layer omni-directional reflectors (ODRs). The ODRs have lower mirror losses than metal reflectors and distributed Bragg reflectors (DBRs). High-reflectivity ODRs have been incorporated into AlGaInP LEDs and GaInN LEDs. It is shown that the ODR signifi...

Fine-pitch backlight technology is rapidly evolving along with display technology, and chips are increasingly designed for direct integration modules. This study used a distributed Bragg reflector (DBR) mini light-emitting diode (mini-LED) backlights high dynamic contrast developed digital twin design by using (LED) (DBR).

We present an ultra-short distributed Bragg reflector fiber laser written in Er/Yb co-doped fiber. The entire laser is only 8.4 mm in length. The lasing threshold is less than 1 mW. The optical signal-to-noise ratio of the laser output is better than 70 dB. The laser emits two orthogonal polarization modes and generates a beat signal with signal-to-noise ratio of approximately 70 dB and 3-dB li...