Why do you think Optics Letters is so highly cited?

Yes, there have been several. In particular, the area of ultrafast optical phenomena has produced the "year’s most-cited article" in Optics Letters in six of the last 10 years. Ultrafast optics encompasses methods to produce, characterize, and utilize light pulses with durations of femtoseconds or less. Although femtosecond lasers have been available since the mid-1970s, the experimental arrangements needed were quite a challenge to maintain. Day-to-day operation required continuing realignment of many complex optical components. Consequently, the field grew slowly despite its enormous potential in chemistry and physics. A breakthrough occurred with the discovery of Kerr-lens mode locking, first published in Optics Letters, which provided a far more simple arrangement. The six highly cited works are among those that contributed to the development of a novel Ti:sapphire laser employing Kerr-lens modelocking. Besides producing record-breaking short-duration pulses, the resultant light source was inherently more stable, easier to maintain, and amenable to commercialization. The much greater convenience of this system led to its increasingly widespread use in science and technology and a surge in the number of citations to this area.

Another exciting development has been the emergence of engineered nanostructured and microstructured optical materials. Examples of these include photonic band-gap materials, left-handed materials, and holey fibers. Light propagating in photonic band-gap materials, for example, behave much like an electron does in a semiconductor. Such metamaterials have, among other properties, strongly modified emissive behavior and are finding use in light-emitting diodes, stealth radar/infrared structures, and ultra low-noise optical detectors. Holey fibers are another example of a microstructured material. These have a regular pattern of micro-capillaries running along the length of the fiber. The effective refractive index of the composite lies between that of air and glass and so these materials may be configured to have properties not obtainable in the usual all-glass optical fibers. Applications envisioned include telecommunications, laser surgery, atom guiding, frequency metrology, and frequency conversion. An example of the latter was an Optics Letters’ article by Ranka et al. in 2000 in which a holey fiber was used to efficiently convert a red ultrafast pulse into a white-light continuum. Based on rate of recent citations, this article was identified by Sci-Bytes as the hottest paper in optics and acoustics published during the previous two years (http://in-cites.com/research/2001/december_17_2001-3.html).

A strong technological driver has been recent interest in optical fiber communication. Many issues important to the success of this concept involve the interaction and propagation of short-duration high-intensity pulses in fibers. So, this has generated a large body of supporting research in nonlinear optical phenomena, optical solitons, and the development of optical components such as switches, filters, and amplifiers needed for this technology. Optical fiber communication is an example of photonics, where photons have been substituted when convenient for electrons in high-speed microcircuits.

Finally, there has been a flurry of activity related to medical and biological aspects of optics. Diagnostics like optical coherence tomography, ultrafast gating, and diffusive wave optics are being employed to extract the image of an object deeply embedded in a highly scattering medium, such as a tumor in tissue. Another popular topic is optical tweezers, in which a tightly focused laser beam is used to trap and manipulate particles. Such tweezers allow fine control over forces as small as a few hundredths of a piconewton and have increased understanding of a wide variety of bio-motor molecules and mechanoenzymes. Other examples include novel nonlinear optical microscopes enabling high-resolution nondestructive chemical analyses in vivo and optical fiber sensors to measure blood-sugar content or to gauge the amount of radiation received during prostate cancer treatment.