Photonics Spectra: University of Bremen This is the syndication feed for Photonics Spectra: University of Bremen. https://www.photonics.com/Splash.aspx?Tag=University+of+Bremen Thu, 28 Mar 2024 13:06:59 GMT Wed, 19 Nov 2014 00:00:00 GMT 1800 Laser Delves Deep into Prehistoric Environments
A look back via laser into sedimentary organic matter that accumulated on the sea floor could shed light on past climates and environments for a better understanding of the future.

A new technique, developed by a team at the University of Bremen’s Center for Marine Environmental Sciences (MARUM), involves laser desorption ionization coupled with Fourier transform ion cyclotron resonance mass spectrometry. This has allowed the researchers to analyze complex organic biomarkers and reconstruct climate conditions in almost 10,000-year-old sediments from the Mediterranean Sea with four-year temporal resolution.

Across a 6-cm section, the researchers looked at the distribution and abundance of lipid biomarkers on the cut...]]>
https://www.photonics.com/Articles/Laser_Delves_Deep_into_Prehistoric_Environments/p5/a56924 A56924 Wed, 19 Nov 2014 00:00:00 GMT
First Micropillars Milled in Warsaw
Rare milling equipment that produces nanosize semiconductor structures, or micropillars, is now at the disposal of scientists and students at the University of Warsaw. These micropillars can be used as efficient light sources and will open up educational possibilities in the field of nanotechnology engineering.

“Being able to generate micropillars directly in the university laboratories is of key importance to our research, especially as regards works on really efficient yellow laser light sources,” said Wojciech Pacuski. The equipment purchased by the Institute of Experimental Physics at the university is one of only a handful of such devices in Poland.

Micropillars are a variety of optical microcavities,...]]>
https://www.photonics.com/Articles/First_Micropillars_Milled_in_Warsaw/p5/a47453 A47453 Mon, 20 Jun 2011 00:00:00 GMT
QDs in microcavities advance blue diode lasers
Newly developed monolithically integrated nitride laser microcavities that incorporate quantum dots (QDs) could be an important step in making better blue and green diode lasers as well as single-photon sources.

A team of solid-state physicists at the University of Bremen were able to introduce InGaN quantum dots into fully epitaxial monolithic microcavities that they grew by metallorganic vapor phase epitaxy. They then added pillar-shaped microcavities by focused ion-beam etching. Their impact was measurable via microphotoluminescence measurements, which showed discrete resonator modes of the microcavities, as well as emission lines of single quantum dots. Pillar-structured microcavities exhibit single-mode emission, which permits...]]>
https://www.photonics.com/Articles/QDs_in_microcavities_advance_blue_diode_lasers/p5/a44613 A44613 Fri, 01 Oct 2010 00:00:00 GMT
Quantum Gas in a Free Fall
Counter to conventional wisdom, researchers say that by dropping a sensitive measuring device, they can actually make the instrument even more sensitive than before.

The team, headed by physicists from the University of Hannover and including scientists from the Max Planck Institute of Quantum Optics, dropped a piece of apparatus in which they generated a weightless Bose-Einstein condensate (BEC), to the bottom of a drop tower at the University of Bremen.

According to the group, the particles in a BEC lose their individuality and can be considered to be a 'superparticle.' The researchers want to use such an ultracold quantum gas at zero gravity to construct a very sensitive measuring device for the Earth's gravitational field...]]>
https://www.photonics.com/Articles/Quantum_Gas_in_a_Free_Fall_/p5/a42662 A42662 Wed, 23 Jun 2010 00:00:00 GMT
Abrasive Vibration Polishing
It’s all about the finishing touches.

To replicate glass and plastic lenses for optical and medical applications – while retaining complex geometries and optofunctional areas in the range of a few millimeters – mold inserts made of steel or carbides have to be finished by polishing.

These complex components must be polished in specific shapes to fit localized cavities or grooves, so rotating polishing pads are very limited, according to a researcher from the University of Bremen in Germany.


Conference attendees register on the first day of Optifab 2009 in Rochester, NY. The technical presentations were already in full swing, but the exhibition hall would not open until the following day. Photo by Laura S. Marshall.
But a...]]>
https://www.photonics.com/Articles/Abrasive_Vibration_Polishing/p5/a37342 A37342 Tue, 12 May 2009 00:00:00 GMT