Peak output power

In high-pressure pulsed CO2 chemical-transfer lasers, peak output powers of 200 KW with 30 /nsec pulse duration have been achieved 408b)... 

This Synchroscan [68] streak camera system has been used to study the time resolved fluorescence of trans-stilbene in the picosecond time regime. The experimental arrangement [69] is shown in Fig. 20. An acousto-optically mode-locked argon ion laser (Spectra Physics 164), modulated at 69.55 MHz was used to pump a dye laser. The fundamental of this dye laser, formed by mirrors M, M2, M3 and M4, was tunable from 565 to 630 nm using Rhodamine 6G and second harmonic output was available by doubling in an ADP crystal placed intracavity at the focal point of mirrors M5 and M6. The peak output power of this laser in the ultraviolet was 0.35W for a 2ps pulse which, when focused into the quartz sample cell of lens L, produced a typical power density of 10 KW cm-2. Fluorescence was collected at 90° to the incident beam and focused onto the streak camera photocathode with lens L3. The fluorescence was also passed through a polarizer and a bandpass filter whose maximum transmission corresponded to the peak of the trans-stilbene fluorescence. 

Apart from these popular tests, Yun and Yun (2013) have used a method in which they stretched a woven PVDF fabric. The fabric was fixed at one end, and the other end was mounted on a custom-designed linear actuation system. The movement of the actuator system was controlled using a stepper motor, which controlled the distance moved and the operational frequency. An oscilloscope was used to record the output voltage. It was claimed that a peak output power of 1.1 mW was achieved, using 20% stretching at 8 Hz ( 0.63 mW cm ). 

Fig. 10. Speed (90—10% fall time) vs peak wavelength for commercial communication LED emitters. Output power levels in mW are given in parentheses.

The advantages of forward-mode eonverters are they exhibit lower output peak-to-peak ripple voltages than do boost-mode eonverters, and they ean provide mueh higher levels of output power. Forward-mode eonverters ean provide up to kilowatts of power. 

Computation of this function results in a three-dimensional plot for which one axis is time delay (or range), the second is Doppler frequency or radial velocity and the third is the output power of the matched filter (usually normalised to unity). The extent of the ambiguity function peak in the Tr and the fd dimensions determines the range and Doppler resolutions respectively. As we are using the directly received signal only we term this self-ambiguity as there is no inclusion of any system geometry dependence on the transmitter and receiver locations. 

Semiconductor lasers can operate in the cw regime (with output powers ranging from /xwatts to tens of watts) or in the pulsed regime, with typical peak powers of tens of watts. 

Table 1 gives wavelengths and output powers for some important laser types operated in a continuous-wave (cw) or pulsed mode. The pulsed lasers normally have much higher peak powers but there are technical or theoretical limitations of the maximum repetition frequency, which means that their time-averaged intensity is often below that of the cw lasers. 

A very interesting device regarding high output power is the photochemical iodine laser 411) where excited iodine atoms are formed by photodissociation of CH3I. Pulses with 5 MW peak power and 5 nsec duration have been produced which could be further amplified in two stages up to 10 W. Energies of 1 K Joule seem to be attainable 412). 

---