LC-filled PC fibers form tunable bandpass filter

Two short sections of optical fiber that combine to become an electrically tunable bandpass filter have been fabricated by scientists at the Technical University of Denmark (Lyngby, Denmark) and NKT Photonics (Birkerød, Denmark). The 10 mm long sections are each large-mode-area solid-core photonic-crystal (PC) fibers with their holes filled with a fluid of liquid-crystal (LC) molecules; the hole diameters and the LC type are different for each section. The two sections are placed serially and butt-coupled in a silicon v-groove containing gold electrodes along the sides of the groove; two single-mode fibers are also held in the ends of the groove and butt-coupled to the sections to couple light in and out of the PC-fiber arrangement.

Light from a supercontinuum-fiber source is coupled into the device. One LC type is a longpass filter and the other a shortpass filter; the combination produces a bandpass filter transmitting over the 1520 to 1680 nm range. When a driving voltage variable between 90 and 120 V is applied to one LC and no voltage to the other, the shortpass edge of the filter can be tuned over a 36 nm bandwidth, with the longpass edge immobile. A similar process applied conversely to the fiber sections produces a longpass tuning range of 12 nm with no shortpass change. Contact Lei Wei at lewe@fotonik.dtu.dk.

More Laser Focus World Current Issue Articles
More Laser Focus World Archives Issue Articles

Most Popular Articles

50 YEARS OF GAS LASERS


Durable survivors evolve new forms

Webcasts

Laser Measurements Critical to Successful Additive Manufacturing Processes

Maximizing the stability of the variables going into any manufacturing process is what ensures ts consistency and high quality. Specifically, when a laser is...

Ray Optics Simulations with COMSOL Multiphysics

The Ray Optics Module can be used to simulate electromagnetic wave propagation when the wavelength is much smaller than the smallest geometric entity in the ...

Multichannel Spectroscopy: Technology and Applications

This webcast, sponsored by Hamamatsu, highlights some of the photonic technology used in spectroscopy, and the resulting applications.

Handheld Spectrometers

Spectroscopy is a powerful and versatile tool that traditionally often required a large and bulky instrument. The combination of compact optics and modern pa...
White Papers

All About Aspheric Lenses

The most notable benefit of aspheric lenses is their ability to correct for spherical aberration....

Wavelength stabilized multi-kW diode laser systems

Wavelength stabilization of high-power diode laser systems is an important means to increase the ...

Narrow-line fiber-coupled modules for DPAL pumping

A new series of fiber coupled diode laser modules optimized for DPAL pumping is presented, featur...
Technical Digests

RAMAN SPECTROSCOPY: The technical advances just keep coming

In Raman spectroscopy, light from a laser interacts with a test sample, undergoing a wavelength s...

ADHESIVES, SEALANTS, AND COATINGS: Solutions for optical technologies

A vast array of optical systems of various types and degrees of complexity require the use of adh...

WAVELENGTH-SWEPT LASERS: Dispersion-tuned fiber laser sweeps over a 140 nm range for OCT

By eliminating the use of mechanical tunable filters and instead tuning by intensity-modulation i...

HIGH-POWER FIBER LASERS: Working in the kilowatt regime

High-power materials-processing fiber lasers are available in an increasing variety of forms, as ...

Click here to have your products listed in the Laser Focus World Buyers Guide.
Social Activity
  •  
  •  
  •  
  •  
  •  
Copyright © 2007-2014. PennWell Corporation, Tulsa, OK. All Rights Reserved.PRIVACY POLICY | TERMS AND CONDITIONS