binary grating code

diff --git a/write_path/write_binary_grating.py b/write_path/write_binary_grating.py
new file mode 100644 (file)
index 0000000..7e002c6
--- /dev/null
+++ b/write_path/write_binary_grating.py
@@ -0,0 +1,97 @@
+"""
+write_binary_grating.py
+Andrew Lorimer, January 2025
+Monash University
+
+Writes a transmission binary grating pattern using
+the confocal direct laser writing setup on Sb2S3 thin-film PCM.
+"""
+
+import configparser as cp
+import cv2
+import numpy as np
+import sys
+import matplotlib.pyplot as plt
+import write_path
+from pipython import datarectools, pitools
+import nidaqmx
+import pipython
+import time
+
+TRANSITION_SPEED = 100   # speed for moving between lines, um/s
+
+# Input parameters
+grating_pitch = 2.7 # Lambda, um
+beam_width = 0.7
+writing_speed = 10  # speed for writing crystallised lines, um/s
+dimensions = (50, 50)   # horizontal * vertical, um
+origin = (0, 0) # horizontal * vertical, um
+
+def wait_target(pidevice, thresh=0.01, axes=[1, 2, 3]):
+    target = pidevice.qMOV(axes)
+    on_target = False
+    while on_target == False:
+        pos = pidevice.qPOS(axes)
+        on_target = True
+        distances = np.abs(np.array(list(pos.values())) - np.array(list(target.values())))
+        on_target = np.all(distances < thresh)
+            
+
+def main(task, pidevice):
+
+    # One block is a solid area with constant refractive index in the 
+    # diffraction grating
+    # One line is a single pass of the laser, with many lines making up a 
+    # block (depending on the beam width)
+
+    n_blocks = int(dimensions[0] // grating_pitch)
+    n_lines = int(grating_pitch // beam_width)
+
+    pidevice.VCO({1: True})
+
+    updown = 0
+
+    for i in range(n_blocks):
+        if (i % 2 == 0):
+            # Even number block - crystallise
+
+            y_block = origin[0] + i * grating_pitch
+
+            for j in range(n_lines):
+                y_line = y_block + j*beam_width
+                x_start = origin[1] + int(not updown)*dimensions[1]
+                x_end = origin[1] + updown*dimensions[1]
+
+                # Go to line start position
+                pidevice.VEL({1: TRANSITION_SPEED})
+                pidevice.MOV({1: x_start, 2: y_line})
+                wait_target(pidevice)
+                time.sleep(0.3)
+                
+                # Write line
+                pidevice.VEL({1: writing_speed})
+                pidevice.MOV({1: x_end, 2: y_line})
+                #time.sleep(0.05)   # compensation for acceleration period
+                task.write(True)
+                wait_target(pidevice)
+                task.write(False)
+                time.sleep(0.3)
+
+                updown = int(not updown)
+        else:
+            # Odd number line - do nothing
+            pass        
+
+if __name__ == "__main__":
+    task, pidevice = write_path.setup()
+    try:
+        main(task, pidevice)
+    finally:
+        print("Exiting")
+        task.write(False)
+        task.close()
+        pidevice.VCO({1: True, 2: True})
+        pidevice.VEL({1: TRANSITION_SPEED, 2: TRANSITION_SPEED})
+        pidevice.MOV({1: origin[1], 2: origin[0]})
+        pitools.waitontarget(pidevice, [1, 2])
+        pitools.stopall(pidevice)