Mode shaping of a graded-reflectivity-mirror unstable resonator with an intra-cavity phase element

Makki, Siamak; Leger, James R.

doi:10.1109/3.892728

Cited by 16 publications

(8 citation statements)

References 10 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…A variety of alternative intra-cavity beam shaping methods have been explored, including amplitude filtering [4], multiple phase filtering [5], and mode shaping in unstable laser resonators [6,7]. In many of these configurations, the ability to discriminate between the fundamental and higher-order modes is enhanced by the resonator design.…”

Section: Beam Shaping Methodsmentioning

confidence: 99%

Beam shaping in laser resonators and coherent laser arrays: an overview and current state of the art

Leger¹,

Khajavikhan²,

Tiffany³

2009

SPIE Proceedings

View full text Add to dashboard Cite

Coherent beam shaping can be performed inside laser resonators by filtering the amplitude or the phase of the circulating wave. Along with providing a designer-shaped output, these methods can improve laser performance by suppressing higher-order modes and extracting maximum gain. Under certain conditions, phase filtering is shown to improve modal discrimination by separating modes into bound (low-loss) modes and unbound (high-loss) modes. Mode shapes in resonator arrays are shown to depend on the architecture of the array. In some cases, these architectures can be designed to improve modal discrimination or increase the tolerance to resonator path-length errors.

show abstract

Section: Beam Shaping Methodsmentioning

confidence: 99%

Beam shaping in laser resonators and coherent laser arrays: an overview and current state of the art

Leger¹,

Khajavikhan²,

Tiffany³

2009

SPIE Proceedings

View full text Add to dashboard Cite

show abstract

“…This analysis shows that even when the dominant mode is a higher-order mode, it is generally a single GL mode, and it should therefore be possible to suppress the mode using intracavity elements, and force the dominant mode back towards the Gaussian, thus enhancing the performance of the FEL. This can be done, for example, by the use of a graded-reflectivity mirror with an intracavity phase element [22], or the inverted relief technique [23].…”

Section: Mode Determinationmentioning

confidence: 99%

Resonator stability and higher-order modes in free-electron laser oscillators

Pathak

Krishnagopal

2014

Phys. Rev. ST Accel. Beams

View full text Add to dashboard Cite

Three-dimensional simulation codes GENESIS and OPC are used to investigate the dependence of the resonator stability of free-electron laser (FEL) oscillators on the stability parameter, laser wavelength, outcoupling hole size and mirror tilt. We find that to have stable lasing over a wide range of wavelengths, the FEL cavity configuration should be carefully chosen. Broadly, the concentric configuration gives near-Gaussian modes and the best performance. At intermediate configurations the dominant mode often switches to a higher-order mode, which kills lasing. For the same reason, the outcoupled power can also be less. We have constructed a simple analytic model to study resonator stability which gives results that are in excellent agreement with the simulations. This suggests that modes in FEL oscillators are determined more by the cavity configuration and radiation propagation than by the details of the FEL interaction. We find (as in experiments at the CLIO FEL) that tilting the mirror can, for some configurations, lead to more outcoupled power than a perfectly aligned mirror because the mode is now a more compact higher-order mode, which may have implications for the mode quality for user experiments. Finally, we show that the higher-order mode obtained is usually a single Gauss-Laguerre mode, and therefore it should be possible to filter out the mode using suitable intracavity elements, leading to better FEL performance.

show abstract

“…The fundamental or lowest-order mode of a multimode laser, fibre or waveguide usually propagates together with an ensemble of higher order modes, comprising a 'natural mode composition'. Many applications require coherent laser beams with a controlled and balanced superposition of modes, including laser beam profile shaping [6], coupling of light into fibres and waveguides [3], optical communications with mode group division multiplexing [7][8][9][10] and laser resonators [11,12].…”

Section: Introductionmentioning

confidence: 99%

Generating function approach for creation of coherent multimode beams by diffractive optics

Shwartz

Golub

Ruschin

2012

Journal of Modern Optics

View full text Add to dashboard Cite

Tailored compositions of transverse modes provided by mathematical generating functions are exploited for the synthesis of multimode laser beams in free space. We show that analytical equations which are available for the generating functions provide physical insight into modal phase and power balance in multimode coherent light beams. Multimode coherent beams were created by methods of diffractive optics implementing the generating functions. Experimental and computer simulated results demonstrate a good match.

show abstract

Mode shaping of a graded-reflectivity-mirror unstable resonator with an intra-cavity phase element

Cited by 16 publications

References 10 publications

Beam shaping in laser resonators and coherent laser arrays: an overview and current state of the art

Beam shaping in laser resonators and coherent laser arrays: an overview and current state of the art

Resonator stability and higher-order modes in free-electron laser oscillators

Generating function approach for creation of coherent multimode beams by diffractive optics

Contact Info

Product

Resources

About