Femtosecond laser microfabrication

We present an overview of femtosecond microstructuring of transparent materials. Bulk structuring of transparent materials can be achieved by focusing high-intensity femtosecond pulses. The morphology of the structures depends on the incident energy per pulse and on the focusing conditions. At high focusing conditions the damage threshold in silicate glasses is just a few nanojoules. This energy range is available from an oscillator. We have demonstrated laser writing of embedded waveguides in silicate glasses with a femtosecond oscillator. Laser machining at high laser repetition rate... Read more about Femtosecond Micromachining of Transparent Materials

The dynamic nature of future optical networks requires high levels of integration, fast response times, and adaptability of the optical components. Laser micromachining circumvents the limitations of planar integration, making three-dimensional integration possible and allowing dense packaging of optical devices with no alignment requirements. Femtosecond micromachining provides the analog of circuit printing by wiring light between various photonic devices as well as printing the actual photonic device into a single or various substrates. Oscillator-only machining has several advantages over... Read more about Optical waveguide fabrication for integrated photonic devices

General Course Description: This interactively taught half-day course provides basic knowledge of the measurements of and research with femtosecond laser pulses. Beginning with the basic principles of the interaction of light and matter, we'll discuss the interaction of intense short pulses with matter. Using worksheets we'll address a number of common conceptual misconceptions in an interactive and collaborative setting.

Benefits Learning outcomes:

This course will enable you to

• Explain the basis for the electronic and optical properties of...

Read more about SC 541: An Introduction to Femtosecond Laser Techniques

When femtosecond laser pulses are focused tightly into a transparent material, the intensity in the focal volume can become high enough to cause nonlinear absorption of laser energy. The absorption, in turn, can lead to permanent structural or chemical changes. Such changes can be used for micromachining bulk transparent materials. Applications include data storage and the writing of waveguides and waveguide splitters in bulk glass, fabrication of micromechanical devices in polymers, and subcellular photodisruption inside single cells.

We recently discovered that 200-nm diameter structures can be created inside transparent materials by ultrafast-laser driven microexplosions. Applications include high-density 3-D data storage, fabrication of 3-D optical elements, and novel materials processing. We present the results of optical and structural examinations and discuss the physical processes involved.

Using femtosecond laser pulses generated by a 25-MHz Ti:Sapphire laser oscillator, we micromachine bulk glass. The laser is focused by a 1.4 numerical aperture microscope objective, allowing the breakdown threshold to be reached with modest energies (4.5 nJ). Single-shot damage is sub-micron in size. Because the pulses arrive faster than energy can diffuse out of the focal volume, multiple shot damage with this laser is thermal in nature. Successive pulses add more and more heat to the sample, melting a micron-sized volume. Using this thermal machining, we have written single-mode waveguides... Read more about Femtosecond laser micromachining of bulk glass at oscillator energies

In recent years, femtosecond lasers have proven to be extremely useful for micromachining the surface and bulk of transparent materials. When a femtosecond laser pulse is focused into a transparent material, the intensity in the focal volume can become high enough to cause absorption through nonlinear processes, leading to optical breakdown and permanent structural change to the material. Because the absorption is nonlinear, this structural change can be localized in the bulk of the sample, allowing a three-dimensional structure to be micromachined. In this paper, we show that by focusing a... Read more about Direct writing of optical waveguides in bulk glass using a femtosecond laser oscillator

When femtosecond laser pulses are focused tightly into a transparent material, the intensity in the focal volume can become high enough to cause nonlinear absorption of laser energy. The absorption, in turn, can lead to permanent structural or chemical changes. Such changes can be used for micromachining bulk transparent materials. Applications include data storage and the writing of waveguides and waveguide splitters in bulk glass, fabrication of micromechanical devices in polymers, and subcellular photodisruption inside single cells. In this talk we will review recent results obtained in... Read more about Femtosecond Laser Micromachining: Applications in Technology and Biology

When femtosecond laser pulses are focused tightly into a transparent material, the intensity in the focal volume can become high enough to cause nonlinear absorption of laser energy. The absorption, in turn, can lead to permanent structural or chemical changes. Such changes can be used for micromachining bulk transparent materials. Applications include data storage and the writing of waveguides and waveguide splitters in bulk glass, fabrication of micromechanical devices in polymers, and subcellular photodisruption inside single cells.

When femtosecond laser pulses are focused tightly into a transparent material, the intensity in the focal volume can become high enough to cause nonlinear absorption of laser energy. The absorption, in turn, can lead to permanent structural or chemical changes. Such changes can be used for micromachining bulk transparent materials. Applications include data storage and the writing of waveguides and waveguide splitters in bulk glass, fabrication of micromechanical devices in polymers, and subcellular photodisruption inside single cells.

Recently there has been much interest in using femtosecond laser pulses in surgical applications. For example, femtosecond lasers could replace the nanosecond systems currently used for opthalmic photodisruption, providing improved surgical precision and adding versatility. In surgical applications, it is the high intensity of femtosecond laser pulses that is exploited. By tightly focusing these short pulses, the intensity becomes high enough to cause nonlinear absorption inside a transparent material (such as the vitreous humor). The absorption produces a hot plasma inside the sample that is... Read more about Laser induced microexplosions: Ultrafast physics with clinical applications

When femtosecond laser pulses are focused tightly into a transparent material, the intensity in the focal volume can become high enough to cause nonlinear absorption of laser energy. The absorption, in turn, can lead to permanent structural or chemical changes. Such changes can be used for micromachining bulk transparent materials. Applications include data storage and the writing of waveguides and waveguide splitters in bulk glass, fabrication of micromechanical devices in polymers, and subcellular photodisruption inside single cells. In this talk we will review recent results obtained in... Read more about Femtosecond laser micromachining of transparent materials for photonics and biology