Laser Sources & Materials
Listing of journals, site links, and abstract of research articles of Laser Sources & Materials
This section is planned to post the list of some important journals, useful site links etc. Abstract of some of the recent research articles indicating the latest research trends along with a detailed bibliography will also be posted.

Suggestions to include any other information in this section are welcome.
  1. Diamonds, a super efficient laser material
  2. Pore-free Ceramics Shine New Light on Lasers, Electronics and Biomedical Implants
  4. Plastic Laser Materials
  5. Characteristics of a continuous-wave Yb:GdVO4 laser end pumped by a high-power diode
  6. Diode-pumped continuous-wave Nd:LuVO4 laser operating at 916nm
  7. Concentration quenching in fine-grained ceramic Nd:YAG

Diamonds, a super efficient laser material

Sydney, April 24:Richard Mildren, associate professor,and his colleagues at the Macquarie University Photonics Research Centre discovered in late 2008 that it was possible to generate a coherent laser beam from synthetic diamond.They have now demonstrated diamond lasers with efficiency higher than almost all other materials.

"The major achievement is that we are able to use synthetic diamond to create high performing laser devices," Mildren said."We are now in a good position to explore the highly exotic laser properties of diamond, many of which are not so widely appreciated."For example, the speed at which heat travels through diamond is the highest of all known materials and it is hoped that this property will enable us to simultaneously miniaturise the device and increase the laser beam power to unprecedented levels."

The diamonds used in the laser research are colourless, approximately eight mm long, and weigh a bit less than a carat.They are grown to the researcher's specifications using a process called chemical vapour deposition that essentially creates the crystal lattice carbon by carbon atom layer by layer on top of a large flat diamond crystal substrate. The synthetic diamond forms the core component of what is called a Raman laser, a type of laser that is optically stimulated rather than electrically powered.

"Though there has been little take up of this type of diamond in the gem market, it is very well suited to our purposes. Diamonds larger than one centimetre are likely to be available very soon which will also be an advantage for our studies."

Diamond is also the most transparent material known, in terms of the range of light wavelengths (or colours) that can pass through the material, said a Macquarie University release

Mildren said satellite borne diamond lasers for mapping greenhouse gases in the atmosphere were also a possibility. He said it is only now - in the 50th year since the invention of the first laser - that the full potential of diamond lasers is starting to be understood.

Pore-free Ceramics Shine New Light on Lasers, Electronics and Biomedical Implants

To most people, the word "ceramics," refers to opaque clay flower pots or translucent porcelain tea cups. But not all ceramics block or scatter light.

Gary L. Messing, distinguished professor of ceramic science and engineering, and his group at Pennsylvania State University, are developing a brand new class of ceramics that are so pure and perfectly transparent, they can be used as a substitute for crystals in solid-state lasers.

To test their new method, Messing and his group made neodymium-doped yttrium aluminum garnet (Nd:YAG) laser ceramics, because they are important in industrial and military applications.The Nd:YAG crystal structure also works well with ceramic processing.

"Most high power, solid-state lasers use single crystals made by melt-growth methods," said Stevenson. "These require high temperatures of greater than 1950 degrees Celsius, and weeks or months to grow a single crystal boule [block] of Nd:YAG."

According to Stevenson, switching to ceramic processing could reduce the temperatures needed to make an Nd:YAG laser ceramic by at least 250 degrees Celsius and reduce the time it takes down to just days.

To make the ceramics, the group started with powders and mixed them with liquids and polymers to make a material similar in consistency to paint. "We used a process called tape casting to make long thin sheets of the material," Messing explained. "Next, we cut the sheets into squares and stacked them to form thicker squares about 1 centimeter x 5 cm x 5 cm."

After applying heat to sinter the squares, the ceramics became transparent. But the material still contained enough pores to degrade a laser's performance."We did a final step, called hot isostatic pressing (HIP), where we heated the ceramics to over 1600 degrees Celsius and applied high pressures with argon gas," Messing said. "By combining heat with pressure, we eliminated the few remaining pores." is supposed to be an Open Source project providing data of modern solid state laser gain media. Primarily, this information board is addressed to laser physicists and laser engineers requiring property parameters and spectra of solid state laser materials.

Still not complete, the data content will be extended. Due to the large number of crystal or glass parameters a certain variation of the presented data must be taken into account.

Although non-commercial this site additionally gives an overview about suppliers and institutions for crystal growth or glass fabrication.

Plastic Laser Materials

A material exhibiting narrow line fluorescence when excited by high-energy radiation, hence suitable for laser applications, is formed by dispersion of rare earth ions bonded to organic molecules in the form of an organometallic chelate, in solid solution in a plastic host.

Characteristics of a continuous-wave Yb:GdVO4 laser end pumped by a high-power diode

Characteristics of a continuous-wave Yb:GdVO4 laser end pumped by a high-power diode

Optics Letters, Vol. 31, Issue 17, pp. 2580-2582

An efficient and compact diode-pumped continuous-wave Yb:GdVO4 laser is demonstrated, generating an output power of 4.0 W with an optical conversion efficiency of 61% and a slope efficiency as high as 78%. With increasing pump power the polarization of the laser output changes from s to p, while in a certain intermediate power range the two polarization states coexist with different emission wavelengths.

Diode-pumped continuous-wave Nd:LuVO4 laser operating at 916nm

Optics Letters, Vol. 31, Issue 10, pp. 1435-1437

We realized an efficient diode-pumped Nd:LuVO4 continuous-wave (CW) laser operating at 916 nm. Laser experiments with 0.5at. % Nd-doped Nd:LuVO4 crystals of various lengths and cutting directions were also investigated. The maximum output power of 930 mW was obtained with a slope efficiency of 27.2% and an optical conversion efficiency of 20.8% at the absorbed pump power of 4.5 W. The laser experiment shows that Nd:LuVO4 crystal can be used for an efficient diode-pumped laser system.

Concentration quenching in fine-grained ceramic Nd:YAG

Optics Express, Vol. 14, Issue 9, pp. 3893-3905

We have studied the concentration dependent fluorescence decay kinetics of ceramic Nd:YAG, to resolve inconsistencies in the previous literature. Our data indicate that earlier reports of single exponential lifetimes even at Nd concentrations of a few percent were due to the effects of long-pulse excitation. Under short-pulse excitation the fluorescence decay is nonexponential for concentrations greater than about 1% atomic. Energy migration to sinks consisting of cross-relaxing Nd ions dominates at long times, whereas single-step energy transfer to randomly distributed quenching sites dominates at earlier times. The concentration dependence of this single-step transfer indicates direct cross-relaxation between individual ions at concentrations below 4% atomic, but resonant transfer to quenching sites consisting of Nd pairs at higher concentrations.


Updated: 6 April, 2015