Liquid dyes lasers

The performance and applicability of the levitated droplet liquid dye laser are challenged by droplet evaporation and bleaching of the laser dye. In order to minimize these effects, Azzouz et al.11 used a measurement scheme, where nominally identical droplets were loaded consecutively, and each droplet was at... 

Chance B, Erecinska M. 1971. Flow flash kinetics of the cytochrome 3-oxygen reaction in coupled and uncoupled mitochondria using the liquid dye laser. Archives of Biochemistry and Biophysics. 143(2) 675-687. 

The rms linewidth of the dye laser has so far been reduced to 300 Hz relative to a reference cavity with the help of an intracavity ADP phase modulator and a fast servo system which compensates for small rapid optical path fluctuations in the liquid dye jet [24]. A perhaps even more elegant alternative is the external laser frequency stabilizer [25] which compensates for phase and frequency noise after the light has left the laser cavity. J. Hall and coworkers [26] have recently reduced the linewidth of a commercial ring dye laser to sub-Hz levels with such a device. 

To discuss solid-state lasers, it is necessary to start with lasers in general. Laser was invented in the 1960s and has been growing quickly, with a wide range of applications in industry, defense, and daily life [2, 9-11]. According the properties of the gain medium used, lasers can be classified into four types (i) semiconductor lasers, (ii) gas lasers, (iii) liquid (dye) lasers, and (iv) solid-state lasers. 

Most excited states of hquids decay so rapidly by collisions with smroimding atoms or molecules (10 sec) that it is difficult to accumulate enough population in an upper laser level to make significant gain. Also, since it is difficult to use electron excitation in liquids, the primary energy source is optical excitation, either by flash lamps or by other lasers. Fluorescing dyes are the best liquid media for lasers. The fact that dyes fluoresce suggests that their... 

In addition to displays, liquid crystals have also been used extensively in tunable photonic devices, such as optical phased array for laser beam steering, variable optical attenuator (VOA) for telecommunications, tunable-focus lens for camera zoom lens, LC-infiltrated photonic crystal fibers [1,2], diode laser-pumped dye-doped LC laser, just to mention a few. 

In general, the atoms or molecules used for laser action are diluted to small concentrations in liquids or solids. Examples are the dye laser, where dye molecules are dissolved in organic solutions at concentrations of 10 to 10 moles/liter, or the ruby laser, where the concentration of the active Cr ions in AI3O3 is on the order of 10 . The optically pumped laser molecules A interact with their surrounding host molecules B. The resulting broadening of the excited levels of A depends on the total electric field produced at the location of A by all adjacent molecules By, and on the dipole moment or the polarizability of A. The linewidth Aco/jt of a tran-... 

We would like to note that the designing of tunable diode lasers is one of the most promising approaches used for the development of gas analyzers aimed for detection of a spedlic gas (Somesfalean et al. 2005). Gas analyzers based on tunable diode lasers are considerably simpler in comparison with conventional systems. A tunable laser is a laser whose wavelength of operation can be altered in a controlled manner. There are many types and categories of tunable lasers. They exist in the gas, liquid, and solid slates. Among the types of tunable lasers are excimer lasers, COj lasers, dye lasers (liquid and solid slate), transition-metal solid-state lasers, semiconductor crystal and diode lasers, and free-electron lasers (Duarte 1995). 

Liquid dyes lasers tunable in the visible range have been known since the middle of the sixties. They are based on organic colorants dissolved in various solvents. The light absorption from the pump source brings the dye molecule to its excited singlet state, and the emission to the terminal vibrational state can then be turned by using appropriate resonant cavities to produce laser emission in the spectral range of fluorescent emission. 

Diao, Z., Huang, W., Peng, Z., Mu, Q., liu, Y., Ma, J., Xuan, L. Anisotropic waveguide theory fta electrically mnable distributed feedback laser from dye-doped holographic polymer dispersed liquid crystal. liq. Cryst. 41, 239-246 (2014)... 

FIashlamp-pumped dye lasers [7.41] have the advantage that they do not need any expensive pump laser. Figure 7.19 shows a commonly used pumping arrangement. The linear flashlamp, filled with xenon, is placed in one of the focal lines of an elliptical cylindric reflector and the flowing liquid dye solution is pumped through a glass tube in the second focal line. The useful maximum... 

Laser action in some dye solutions was first discovered by Lankard and Sorokin in 1966. This led to the first laser which was continuously tunable over an appreciable wavelength range. Dye lasers are also unusual in that the active medium is a liquid. 

Liquid crystal polymers are also used in electrooptic displays. Side-chain polymers are quite suitable for this purpose, but usually involve much larger elastic and viscous constants, which slow the response of the device (33). The chiral smectic C phase is perhaps best suited for a polymer field effect device. The abiHty to attach dichroic or fluorescent dyes as a proportion of the side groups opens the door to appHcations not easily achieved with low molecular weight Hquid crystals. Polymers with smectic phases have also been used to create laser writable devices (30). The laser can address areas a few micrometers wide, changing a clear state to a strong scattering state or vice versa. Future uses of Hquid crystal polymers may include data storage devices. Polymers with nonlinear optical properties may also become important for device appHcations. 

A versatile Laser-SNMS instrument consists of a versatile microfocus ion gun, a sputtering ion gun, a liquid metal ion gun, a pulsed flood electron gun, a resonant laser system consisting of a pulsed Nd YAG laser pumping two dye lasers, a non-resonant laser system consisting of a high-power excimer or Nd YAG laser, a computer-controlled high-resolution sample manipulator on which samples can be cooled or heated, a video and electron imaging system, a vacuum lock for sample introduction, and a TOF mass spectrometer. 

The common liquid lasers utilize a flowing dye as the active medium and are pumped by a flash lamp or another laser. These are typically more complex systems requiring more maintenance. They can he operated as either CW (continuous wave) or pulsed. One advantage liquid lasers have is they can be tuned for different wavelengths over a 100-nm range. 

---