Luxpop For index of refraction values and other photonics calculations

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Gaussian Beam Propagation

Perform calculations on Gaussian beam transformation by a lens. Notes: a) for these calculations the beam waists do not necessarily need to be at the focus, b) results for negative focal length lens may be suspect.
Parameters: d1,d2 (in millimetres): distance from beam waist to lens; w1, w2 (microns): 1/e2 beam radii at the waist; f (millimetres): lens focal length; l (nm): wavelength.

If you enter d1, w1, f and l, the algorithm will return d2 and w2; additionally, the algorithm will return wL, the 1/e2 beam radius (although wL is not at a waist) at the lens.

Additional "sweeping" feature: if one sweep value is entered, Luxpop will perform 9 calculations within a range bounded by the sweep parameter.

ModeMatching_GaussianBeam.gif

                 d1: mm   w1: mm            f:  mm       l: nm            
      sweep:    mm        mm             mm         nm

Return the Rayleigh range and far field divergence angle given an initial 1/e2 beam radius  at the waist , wo (mm), and a wavelength, l (nm).

wo: mm        l:nm   

Return the 1/e2 beam radius  (in mm) given a distance from the waist , z (mm), a beam radius at the waist, wo (mm), and a wavelength l (nm). Additional "sweeping" feature: if one sweep value is entered, Luxpop will perform 15 calculations within a range bounded by the sweep parameter.

z:   mm     sweep: mm about nominal values
wo:mm     sweep: mm about nominal values
l:   nm     sweep: nm about nominal values       

Conversions
Convert between photon energy (in eV) , wavelength (nm in vacuum), frequency (Hz), and wavenumber (cm-1).
Enter one parameter below and the three other equivalent values will be returned.
Scientific notation is acceptable. Example: entering 192.2e12 for the frequency will properly be interpreted to mean 192.2 THz.

Photon energy: eV     wavelength: nm         frequency: Hz         wave number: cm-1         

Convert complex index of refraction to complex permittivity   or vice versa.
Enter a value for either (i) n and k or (ii) the complex permittivities

        n:            k:              e1:               e2:                        

Convert absorption coefficient (alpha or a) to coefficient (k)   or vice versa.
Enter a value for (i) either alpha or k and (ii) wavelength (nm)

        k:            alpha: dB/cm              l: nm

Return the differential frequency or wavelength  (in GHz or nm) for a given differential wavelength or frequency, centered at the given wavelength.
If dl is entered, then the differential frequency will be computed, and vice-versa.

 dl: nm    df: GHz     l: nm 

Return the finesse for a resonator with the given refractive index, thickness, and reflectivity.
refractive index:      thickness: mm      reflectivity: %  

Return the coherence length   of a source given a FWHM  linewidth (either in GHz or nm, absolute value ) and a centre wavelength (in nm).
Enter *either* a GHz value *OR* a nm value for the FWHM

Note:  for narrow linewidths, feel free to enter the frequency in scientific notation. e.g. For a 50 MHz linewidth, enter 50e-3 GHz.

    FWHM:   GHz   OR  nm                    centre wavelength: nm

Return the lateral shift, d, (in mm) of a beam with an incident angle of q (in degrees) on a substrate of thickness t (in mm) with index of refraction n. Ambient index of refraction assumed to be 1.

Subs_shift.gif (1542 bytes)

t:mm                  n:                 q: degrees 

Optical Parametric Oscillators

Determine the grating period, Lg, of a PPLN-based QPM OPO given the pump wavelength,  lp (in nm),  the desired signal wavelength, ls (in nm), the temperature Tdes (in °C) at which the OPO is designed to operate, and the order, m, of the QPM. The algorithm determines the operating point by the simultaneous solution of the energy conservation and momentum (phase matching) conditions. For proper results, Luxpop uses the  indices of refraction (ni,ns,np) as calculated by the  temperature-dependent Sellmeier coefficients for the appropriate respective wavelength, as implemented in Luxpop's index of refraction calculation section.  

This OPO calculation assumes collinear interaction with all waves polarized extraordinary to the optical axis (eee configuration). The algorithm will also give the idler wavelength for the operating point.

  lp:nm        ls: nm          Tdes  °C       m:  

Feel free to contact us to request further improvements, enhancements, or new OPO functions.

Determine the impact of temperature fluctuations on the signal wavelength, ls (in nm), of a given  PPLN-based QPM OPO design.

Given an OPO of order m, and pump wavelength lp (in nm) designed to generate a signal wavelength ls at a temperature Tdes, determine how a different actual temperature Tact will affect the generated signal wavelength l's.

When determining the impact of temperature change Luxpop considers two factors: 1) the change in the indices of refraction, ni, ns, and np   as the temperature changes, and 2) the thermal expansion of the PPLN substrate material which causes the grating period to change.

This OPO calculation assumes collinear interaction with all waves polarized extraordinary to the optical axis (eee configuration). The algorithm will also give the idler wavelength and the rest of the actual operating point.

    ls: nm          lp: nm       m:          Tdes  °C       Tact: °C           

Feel free to contact us to request further improvements, enhancements, or new OPO functions.

Polarization

Calculate the resulting Stokes Vector emerging from an optical system composed of up to 5 polarization components.

The user supplies the input vector and the components. The algorithm will compute the resuting Stokes Vector. The optical system is set up such that the light first goes through component #1, then #2, then #3 and so on. If there are less than 5 components, just choose "no component" for the remaining components.

For all components, the nominal angle,  q (in degrees), represents the rotation from the horizontal. In addition, for retardance components, the specified angle indicates the angular orientation of the fast axis.

Input Stokes Vector:


Component #1:        q: deg.

Component #2:        q: deg.

Component #3:        q: deg.

Component #4:        q: deg.

Component #5:        q: deg.