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The instrument obtains voltage waveform and timing information by monitoring the interaction of laser light with the changes in the electric field across a p-n junction. As the laser reaches the silicon surface, a certain amount of that light is reflected back. The amount of reflected laser light from the junction is sampled at various points ...
Q-switching, sometimes known as giant pulse formation or Q-spoiling, [1] is a technique by which a laser can be made to produce a pulsed output beam. The technique allows the production of light pulses with extremely high peak power, much higher than would be produced by the same laser if it were operating in a continuous wave (constant output) mode.
The laser diode chip removed and placed on the eye of a needle for scale A laser diode with the case cut away. The laser diode chip is the small black chip at the front; a photodiode at the back is used to control output power. SEM (scanning electron microscope) image of a commercial laser diode with its case and window cut away. The anode ...
A PIN diode switch can switch much more quickly (e.g., 1 microsecond), although at lower RF frequencies it isn't reasonable to expect switching times in the same order of magnitude as the RF period. For example, the capacitance of an "off"-state discrete PIN diode might be 1 pF. At 320 MHz, the capacitive reactance of 1 pF is 497 ohms:
The transmission of an etalon as a function of wavelength. A high-finesse etalon (red line) shows sharper peaks and lower transmission minima than a low-finesse etalon (blue). The free spectral range is Δλ (shown above the graph). The FSR is related to the full-width half-maximum δλ of any one transmission band by a quantity known as the ...
The most basic optical tweezer setup will likely include the following components: a laser (usually Nd:YAG), a beam expander, some optics used to steer the beam location in the sample plane, a microscope objective and condenser to create the trap in the sample plane, a position detector (e.g. quadrant photodiode) to measure beam displacements ...
A technique that is commonly employed in these devices is cascading, first proposed in 1994: [5] The "first-order" laser light that is generated from the pump light in a single frequency-shifting step remains trapped in the laser resonator and is pushed to such high power levels that it acts itself as the pump for the generation of "second ...
The laser induces local thermal gradients in the device, which result in changes to the amount of power that the device uses. A laser is scanned over the surface of the device while it is under electrical bias. The device is biased using a constant current source, and the power supply pin voltage is monitored for changes.