bmarechal / PM100_waist

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  1 +from scipy.optimize import curve_fit
  2 +import csv, numpy, glob
  3 +from scipy.special import erf
  4 +import matplotlib.pyplot as plt
  5 +
  6 +'''power function to optimize'''
  7 +def P(x, Po, Pmax, xo, w):
  8 + return Po+0.5*Pmax*(1.-erf(2.**0.5*(x-xo)/w))
  9 +
  10 +
  11 +'''load and fit beam section'''
  12 +files = glob.glob('*.dat')
  13 +files.sort()
  14 +data_waist = []
  15 +plt.close()
  16 +fig, p = plt.subplots(2, 1)
  17 +for f in files:
  18 + with open(f, 'r') as dest_f:
  19 + raw = csv.reader(dest_f, delimiter = '\t', quotechar = '"')
  20 + data = [value for value in raw]
  21 + data = numpy.asarray(data, dtype = float)
  22 + xmes = data[:,0]
  23 + Pmes = data[:,1]
  24 +
  25 + '''optimization with non-linear least squares method'''
  26 + Ppopt, Pcov = curve_fit(P, xmes, Pmes)
  27 + data_waist.append([int(f[-7:-4]), Ppopt[3]])
  28 +
  29 + '''plot'''
  30 + p[0].plot(xmes, Pmes, 'o')
  31 + p[0].plot(numpy.linspace(xmes[0], xmes[-1], 100), P(numpy.linspace(xmes[0], xmes[-1], 100), *Ppopt))
  32 +
  33 +p[0].grid()
  34 +
  35 +'''return waist(z) table'''
  36 +data_waist = numpy.asarray(data_waist, dtype = float)
  37 +print(data_waist)
  38 +
  39 +'''waist function to optimize'''
  40 +def W(z, w0, z0):
  41 + return w0*(1.+((z-z0)*1542e-6/(numpy.pi*w0**2))**2)**0.5
  42 +
  43 +popt, cov = curve_fit(W, data_waist[:,0], data_waist[:,1])
  44 +print(popt[0], popt[1])
  45 +
  46 +p[1].plot(data_waist[:,0], data_waist[:,1], 'bo')
  47 +p[1].plot(data_waist[:,0], -data_waist[:,1], 'bo')
  48 +p[1].plot(numpy.linspace(data_waist[0,0], data_waist[-1,0], 100), W(numpy.linspace(data_waist[0,0], data_waist[-1,0], 100), *popt), 'r')
  49 +p[1].plot(numpy.linspace(data_waist[0,0], data_waist[-1,0], 100), -W(numpy.linspace(data_waist[0,0], data_waist[-1,0], 100), *popt), 'r')
  50 +p[1].grid()
  51 +
  52 +plt.show()
  1 +#!/usr/bin/env python
  2 +
  3 +import argparse, time, os
  4 +import matplotlib.pyplot as plt
  5 +
  6 +#==============================================================================
  7 +
  8 +# Path
  9 +PATH = os.getcwd()
  10 +# File footer
  11 +OFILENAME = '130'
  12 +
  13 +#==============================================================================
  14 +
  15 +def parse():
  16 + """
  17 + Specific parsing procedure for transfering data from Thorlabs PM100D.
  18 + :returns: populated namespace (parser)
  19 + """
  20 + parser = argparse.ArgumentParser(description = 'Acquire data from Thorlabs PM100D',
  21 + epilog = 'Example: \'./pm100d.py -st 10 -o toto\' logs PM100D every 10 seconds to output file YYYYMMDD-HHMMSS-toto.dat')
  22 +
  23 + parser.add_argument('-p',
  24 + action='store',
  25 + dest='path',
  26 + default=PATH,
  27 + help='Absolute path (default '+PATH+')')
  28 +
  29 + parser.add_argument('-o',
  30 + action='store',
  31 + dest='ofile',
  32 + default=OFILENAME,
  33 + help='Output data filename (default '+OFILENAME+')')
  34 +
  35 + args = parser.parse_args()
  36 + return args
  37 +
  38 +#==============================================================================
  39 +
  40 +class usbtmc:
  41 + def __init__(self, device):
  42 + self.device = device
  43 + self.FILE = os.open(device, os.O_RDWR)
  44 +
  45 + def write(self, command):
  46 + os.write(self.FILE, command);
  47 +
  48 + def read(self, length = 4000):
  49 + return os.read(self.FILE, length)
  50 +
  51 + def getName(self):
  52 + self.write("*IDN?")
  53 + return self.read(300)
  54 +
  55 + def sendReset(self):
  56 + self.write("*RST")
  57 +
  58 +#==============================================================================
  59 +
  60 +class instrument:
  61 + """Class to control a SCPI compatible instrument"""
  62 + def __init__(self, device):
  63 + print 'Connecting to device %s...' %device
  64 + self.meas = usbtmc(device)
  65 + self.name = self.meas.getName()
  66 + print self.name
  67 + print ' --> Ok'
  68 +
  69 + def write(self, command):
  70 + """Send an arbitrary command directly to the scope"""
  71 + self.meas.write(command)
  72 +
  73 + def read(self, command):
  74 + """Read an arbitrary amount of data directly from the scope"""
  75 + return self.meas.read(command)
  76 +
  77 + def reset(self):
  78 + """Reset the instrument"""
  79 + self.meas.sendReset()
  80 +
  81 + def value(self):
  82 + self.write('MEAS?')
  83 + return self.read(300)
  84 +
  85 +#==============================================================================
  86 +
  87 +def acqu_PM100D(instrument, path, ofile):
  88 +
  89 + t0 = time.time()
  90 + filename = time.strftime("%Y%m%d-%H%M%S", time.gmtime(t0)) + '-' + ofile + '.dat'
  91 + print('Opening %s' %filename)
  92 + data_file = open(filename, 'wr', 0)
  93 + dx = 0.
  94 +
  95 + xmes = []
  96 + Pmes = []
  97 + plt.ion()
  98 + fig = plt.figure()
  99 + ax1 = fig.add_subplot(111)
  100 + line1, = ax1.plot(xmes, Pmes, 'o')
  101 +
  102 + # Infinite loop
  103 + while True:
  104 + try:
  105 + keypressed = raw_input("Press Enter to continue...\n")
  106 +
  107 + if keypressed=='':
  108 + # Power values
  109 + sensors_values = instrument.value()
  110 + sensors_values = sensors_values.replace('E', 'e')
  111 + string = "%f\t%s" % (dx , sensors_values)
  112 + data_file.write(string) # Write in a file
  113 + print(string)
  114 +
  115 + xmes.append(dx)
  116 + Pmes.append(float(sensors_values))
  117 +
  118 + dx = dx + 0.05
  119 +
  120 + elif keypressed.isdigit():
  121 + print('Closing %s' %filename)
  122 + data_file.close()
  123 + t0 = time.time()
  124 + filename = time.strftime("%Y%m%d-%H%M%S", time.gmtime(t0)) + '-' + keypressed + '.dat'
  125 + print('Opening %s' %filename)
  126 + data_file = open(filename, 'wr', 0)
  127 + dx = 0.
  128 +
  129 + xmes = []
  130 + Pmes = []
  131 + line1, = ax1.plot(xmes, Pmes, 'o')
  132 +
  133 + else:
  134 + raise KeyboardInterrupt
  135 +
  136 +
  137 + line1.set_data(xmes, Pmes)
  138 + ax1.relim()
  139 + ax1.autoscale_view()
  140 + fig.canvas.draw()
  141 +
  142 + except Exception as ex:
  143 + print 'Exception during controler data reading: ' + str(ex)
  144 +
  145 + except KeyboardInterrupt:
  146 + print '\n --> Disconnected'
  147 + data_file.close()
  148 +
  149 + # To stop the loop in a clean way
  150 + break
  151 +
  152 +#==============================================================================
  153 +
  154 +def main():
  155 + """
  156 + Main script
  157 + """
  158 + # Parse command line
  159 + args = parse()
  160 + # path
  161 + path = args.path
  162 + # Data output filename
  163 + ofile = args.ofile
  164 +
  165 + try:
  166 + pm100 = instrument("/dev/usbtmc0")
  167 +
  168 + # acquisition with 2 sec. timeout
  169 + acqu_PM100D(pm100, path, ofile)
  170 +
  171 + except Exception as ex:
  172 + print 'Oups '+str(ex)
  173 + print 'Program ending\n'
  174 +
  175 +#==============================================================================
  176 +
  177 +if __name__ == "__main__":
  178 + main()