Power Splitters

Figure 11. 4-port devices power splitter, relative phase shifter, directional coupler. 

The characteristics of those basic entities like power splitters, combiners, directional couplers etc. can be related to some basic waveguide properties, and the 4-port devices are described by 2 x 2 matrices, Eqs(28),... 

Figure 2. (a) A schematic diagram of a 2D MMI 1 x 65 power splitter, and (b) a 3D FD-BPM simulation of the output intensity distribution showing 1 x 65 power splitting. 

Figure 3. (a) A comparison of uniformity for the 1x65 planar and 2D MMI power splitters, (b) A eomparison of the bandwidth of the 1x65 planar and 2D MMI power splitters. 

In this work, we presented the 2D MMl couplers as a basic component for 3D integrated optics. Two basic applications of the 2D MMl, the power splitter and 3D MMl PHASAR, are studied and compared to their planar equivalent. The simulations show an appreciable performance enhancement in both cases. These promising devices open the door to multilevel integrated optical circuits with higher packing density and better performance. 

Steier and co-workers have used such processing techniques to fabricate a variety of devices such as the 1x4 power splitter and polarization splitter shown in Figs. 27 and 28, respectively. 

Fig. 10 Dual photomultiplier scheme for fluorescent detection. EP - emitted photon stream from the sensing volume, PS - fiberoptic power splitter, ND -neutral density Alter, PMTx -photomultiplier, El, E2,...

The magic-tee is inherently noisy because the receiver sees noise not only from the tank circuit but also from the dummy load and because half of the signal from the tank circuit is sent back towards the transmitter. The easy way out of this limitation is to use a directional coupler instead of a magic-tee. A directional coupler, also described further in V. C. 10., is a three port device which amounts to an asymmetric power splitter and it works well as a duplexer. The isolation between the receiver and the transmitter is achieved when the tank circuit impedance is adjusted to be a real and specified value, just as with the magic-tee. The attenuated path is placed between the transmitter and the tank circuit which means that more input power is required than with a magic-tee... 

For pulse-by-pulse multiplexing, the timing reference signal for the TCSPC channels comes from one of the lasers. For pulse group multiplexing, the trigger output signals of the lasers are combined in a reversed power splitter. 

Fig. 7.50 Reflection-free attenuator (left) and reflection-free power splitter (right)...

If a signal has to be distributed into several loads, e.g. to trigger two TCSPC modules from the same laser, a resistive network must be used as well. A 1 2 power splitter" is shown in Fig. 7.50, right. 

A wide range of attenuators is available for the commonly used SMA and BNC connector systems. Power splitters are available for splitting a signal into 2, 3 or 4 outputs. The signal amplitude at the outputs is 1/2, 1/3 and 1/4 of the input amplitude, respectively. Unused outputs of a power splitter must be terminated by 50 resistors. Attenuators and power splitters of satisfactory bandwidth can be made by soldering small 0805-size surface-mount resistors directly between the pins of SMA connectors. 

Figure 1. Schematic of the new single-fiber-baeed multifrequency phase and modulation fluorometer. Abbreviations represent BT, mirrored beam translator M, mirrors PBS, polarizing beam splitter PC, Pockel s cell Freq. Syn., frequency synthesizers PA1 and PA2, power amplifiers BS, beam splitter PM, perforated mirror D, photomultiplier tube detector BPF, band-pass filters x,y,z, x,y,z translation stage PS, power splitter.

The back-scattered fluorescence is collected back up the same fiber, reflected from the mirrored face of the perforated mirror (PM), and imaged by another lens onto the entrance slit of a monochromator (SLM-Aminco, Inc.) with a spectral band-pass of 8 nm. Fluorescence is detected with another photomultiplier tube (D), identical to the reference channel unit. The cross-correlation (heterodyne) frequency (16,18) is produced with a second PTS 500 frequency synthesizer amplified by a 5W power amplifier (PA2 Amplifier Research, model 5W1000). The output from this amplifier is directed simultaneously to the second dynodes of the both reference and detection photomultiplier tubes using a simple power splitter (PS Adam Russell, model H-9). The cross-correlation frequency employed for this instrument is 25 Hz. 

For optical applications, inorganic silicate-based oxide [2], non-oxide sulfide [3], and hybrid [4] and nanocomposite thin films [5] have been extensively studied, for passive or active optical components in integrated optical applications, including power splitters, Er " -dof>ed optical amplifiers for dense wavelength division multiplexer (DWDM) systems, and Au nanoparticle (NP)-doped optical sensors. However, sol-gel-derived materials may often differ from their melt-quenched analogues, even for the simple compoimd Si02- In these... 

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