Panasonic, the leading brand by which Matsushita Electric Industrial Co., Ltd. is generally known, today announced the development of the 850 nm AlGaAs/GaAs VCSEL (Vertical Cavity Surface Emitting Laser) capable of high speed 12.5 Gbps modulation at low operating current of 8 mA. This laser will be used for a low-cost optical communication such as plastic fiber communication and spatial light transmission.
For high-speed operation, it is essential to reduce the parasitic capacitance in the laser. The developed VCSEL has our original planarized structure using BCB (benzocyclobutene) resin with low dielectric constant formed around the light emitting post structure. This structure hugely reduces the parasitic capacitance to less than one third of the conventional value from 0.7 pF to 0.2 pF. This has doubled the modulation bandwidth previously limited by the parasitic capacitance, realizing the world's highest data transmission rate of 12.5Gbps with 12 GHz relaxation oscillation frequency.
In addition, the optimization of the device structure employing current confinement by selective oxidation has realized a low threshold current of 1 mA, a high slope efficiency of 1.1 W/A that is almost three times higher than the conventional value. This has resulted in a low operating current of 8mA for 12.5Gbps modulation.
Panasonic aims to begin shipping the two types of surface emitting lasers (2.5 Gbps and 12.5 Gbps) in early 2006. Applications for forty domestic and nine international patents have been filed. These research and development results have been presented at Conference on Lasers and Electro-Optics (CLEO) 2005, held in Baltimore, U.S. from May 22 to 27, 2005.
Related stories:
Honest lovers? Fallow buck groans reveal their status and size during the rut
It is known that the phonic structure of calls produced by males during the breeding season may signal quality-related characteristics in many different types of animals. Previous research on mammals has mainly focussed on the relationship between the acoustic components of vocalizations and one aspect of male quality: body size.
Electrons discover their individuality
(PhysOrg.com) -- Electrons have something in common with people: the more information they acquire about their setting, the more they become aware of their individuality and the more belonging to a group loses its importance. As a result, the coherent harmony that binds the electrons into a fixed relationship with their environment is lost. This is what scientists at the Fritz-Haber Institute of the Max-Planck Society discovered when, with the aid of X-rays, they catapulted electrons out of molecules consisting of two nitrogen atoms.
Key discovered to cold tolerance in corn
Demand for corn -- the world's number one feed grain and a staple food for many -- is outstripping supply, resulting in large price increases that are forecast to continue over the next several years. If corn's intolerance of low temperatures could be overcome, then the length of the growing season, and yield, could be increased at present sites of cultivation and its range extended into colder regions.
Magnetism and Superconductivity Observed to Exist in Harmony
(Physorg.com) -- Physicists at Los Alamos National Laboratory, along with colleagues at institutions in Switzerland and Canada, have observed, for the first time in a single exotic phase, a situation where magnetism and superconductivity are necessary for each other's existence.
Ceramic material revs up microwaving
Quicker microwave meals that use less energy may soon be possible with new ceramic microwave dishes and, according to the material scientists responsible, this same material could help with organic waste remediation.
Why wind turbines can mean death for bats
Power-generating wind turbines have long been recognized as a potentially life-threatening hazard for birds. But at most wind facilities, bats actually die in much greater numbers. Now, researchers reporting in
Current Biology, a Cell Press journal, on August 26th think they know why.
Internet provider's usage cap raises questions
(AP) -- Three months ago, Guy Distaffen switched Internet providers, lured from his cable company to his phone company by a year of free service on a two-year contract. But soon the company quietly updated its policies to say it would limit his Internet activity each month.
Large area transistors get helping hand from quantum effects
Researchers from the Hitachi Central Research Laboratory, Japan, and the Advanced Technology Institute of the University of Surrey today report that nano-designed transistors for the large area display and sensor application field benefit hugely from quantum size effects.
