def run_offset(SpecAn, freq = 1.45*GHz, span = 2.9*GHz, res = 30*kHz, sweep = 50*ms, full_span = 'Y', show_window = 'N'):
''' Sets desired SpecAn settings and runs Milos's background and free run
programs.'''
SpecAn.write("CF " + str(freq))
SpecAn.write("SP " + str(span))
SpecAn.write("RB " + str(res))
SpecAn.write("ST " + str(sweep))
SpecAn.write('VB ' + str(1000))
sleep(0.5)
SIH.save_offset(20, full_span)
if show_window == 'Y':
SIH.free_run_plot_window('Y', freq, span, full_span)
def background(SpecAn, freq, span, res = 10*kHz, sweep = 1*s):
''' Semi automates the background measurements on the HP8560E '''
#First step laser off the absorption
#Set SpecAn to be a desired freq, span...
SpecAn.write('CF ' + freq)
SpecAn.write('SP ' + span)
SpecAn.write('RB ' + res)
SpecAn.write('ST ' + sweep)
#Run background measurement.
SIH.save_offset(3)
#Set span back to full so laser can be stepped back to absorption
full_sweep(SpecAn)
def holeburn(offset = 'N', args = [1.45*GHz, 2.9*GHz, 30*kHz, 1*s]):
''' No longer use this '''
if offset != ('Y' or 'N'):
raise error('argument must be "Y" or "N"')
elif offset == 'Y':
#Set SpecAn stuff
SpecAn.write("CF " + str(args[0]))
SpecAn.write("SP " + str(args[1]))
SpecAn.write("RB " + str(args[2]))
SpecAn.write("ST " + str(args[3]))
sleep(0.5)
SIH.save_offset(20)
pb.hole_burn(3*s)
SIH.free_run_plot_window('Y')
def run_offset(SpecAn,
freq=1.45 * GHz,
span=2.9 * GHz,
res=30 * kHz,
sweep=50 * ms,
full_span='Y',
show_window='N',
n=20):
''' Sets desired SpecAn settings and runs Milos's background and free run
programs.'''
SpecAn.write("CF " + str(freq))
SpecAn.write("SP " + str(span))
SpecAn.write("RB " + str(res))
SpecAn.write("ST " + str(sweep))
#This sequence ensures that atleast one sweep is taken once the Span and Center
#Frequecies are changed, before the offsets are saved
pb.Sequence([(['ch2', 'ch4', 'ch5'], 50 * ms), ([], 0.4 * s)], loop=False)
sleep(0.5)
SIH.save_offset(n, full_span)
if show_window == 'Y':
SIH.free_run_plot_window('Y', freq, span, full_span)
def laser_stability_measure(freq,
t_space=100 * ms,
t=4 * s,
f_name='',
show='Y'):
[SpecAn, SpecAn_Bool] = Initialise_HP8560E_SpecAn()
SpecAn.write('ST 0.05') #Sweep Time 50ms
n = int(t / t_space) #Amount of times scans needed
## mc.setup(centerFreqL = freq, widthL = 10e4, sweepTimeL = 1e-4)
if t_space < 50 * ms:
raise RuntimeError, "SpecAn's fastest sweep time & reset is 100ms, t_space cannot be faster."
file = make_file(f_name)
span = 5 * MHz
freq_sit = freq
SpecAn.write('CF ' + str(freq_sit))
SpecAn.write('SP ' + str(span))
time.sleep(0.5)
#Take Background measurement
SIH.save_offset(10, 'n')
#Burn a hole
pb.Sequence([(['ch1'], 50 * ms), (['ch2', 'ch4', 'ch5'], 1 * ms)],
loop=False)
HP8560E_SpecAn_Trigger('EXT', 'CONTS', SpecAn)
print "Recording for {}s at {} Hz".format(t, 1 / t_space)
#Get raw data
l = []
for k in range(n):
l.append([time.time(), getTrace(SpecAn, t_space)])
HP8560E_SpecAn_Trigger('FREE', 'CONTS', SpecAn)
t_init = l[0][0]
t_arr = []
center = []
freq_arr = np.linspace(freq_sit - span / 2, freq_sit + span / 2, 601)
for i in range(n):
#Convert to dB and background subtract post data collection
dat = SIH.convert2db(SpecAn, l[i][1])
dat = hb.compensate(dat, span)
#Make time and freq peak array
t_arr.append(l[i][0] - t_init)
index = np.argmax(
dat[50:]) #The carrier also makes a hole, this should ignore it
center.append(freq_arr[index])
data = np.vstack([t_arr, center]).T
np.savetxt(file, data, fmt='%.10e')
##
pb.Sequence([(['ch2', 'ch5', 'ch4'], 1 * ms)], loop=False)
#Plot
if show == 'Y':
plt.plot(t_arr, center)
plt.show()
return l, t_arr, center, data