import sys import numpy as np import matplotlib.pyplot as plt from matplotlib.patches import FancyArrowPatch, Rectangle, FancyBboxPatch from matplotlib.lines import Line2D output_path = sys.argv[1] # --------------------------------------------------------------------------- # Colors # --------------------------------------------------------------------------- c_bg = "#0b1020" c_box = "#1b2544" c_edge = "#4a5a8a" c_text = "#f2f3fb" c_mirror = "#eef0f7" c_bs = "#7fd8ff" c_beam_out = "#ff5a5a" # outgoing beam (laser -> arms) c_beam_return = "#ffb454" # returning beam (arms -> beam splitter) c_beam_combined = "#c77dff" # recombined beam -> screen fig, ax = plt.subplots(figsize=(12, 9), dpi=100) fig.patch.set_facecolor(c_bg) ax.set_facecolor(c_bg) ax.set_xlim(-7.8, 7.8) ax.set_ylim(-6.6, 6.9) ax.set_aspect("equal") ax.axis("off") # --------------------------------------------------------------------------- # Symmetric layout: Beam Splitter (BS) sits at the origin. # Laser --------- BS --------- Mirror B (horizontal axis) # | # Mirror A (up arm) # | # BS # | # Screen (down arm) # --------------------------------------------------------------------------- BS = (0.0, 0.0) LASER_X = -5.6 MIRROR_B_X = 5.6 MIRROR_A_Y = 4.6 SCREEN_Y = -4.6 GAP = 0.18 # clearance around the beam-splitter center so beams don't overlap it def arrow(start, end, color, lw=2.6, mutation=18, alpha=1.0, z=3): a = FancyArrowPatch( start, end, arrowstyle="-|>", mutation_scale=mutation, color=color, linewidth=lw, alpha=alpha, shrinkA=0, shrinkB=0, zorder=z, ) ax.add_patch(a) # --------------------------------------------------------------------------- # Laser # --------------------------------------------------------------------------- laser_box = FancyBboxPatch( (LASER_X - 1.1, -0.55), 1.7, 1.1, boxstyle="round,pad=0.04,rounding_size=0.1", facecolor=c_box, edgecolor=c_edge, linewidth=1.8, zorder=4, ) ax.add_patch(laser_box) ax.text(LASER_X - 0.25, 0, "LASER", color=c_text, fontsize=13, fontweight="bold", ha="center", va="center", zorder=5) ax.add_patch(Rectangle((LASER_X + 0.6, -0.08), 0.25, 0.16, facecolor=c_beam_out, edgecolor="none", zorder=5)) # --------------------------------------------------------------------------- # Beam splitter: a thin plate tilted at 45 degrees through the origin # --------------------------------------------------------------------------- bs_len = 1.05 diag = bs_len * np.cos(np.radians(45)) ax.plot([-diag, diag], [-diag, diag], color=c_bs, linewidth=7, solid_capstyle="round", alpha=0.9, zorder=6) ax.plot([-diag, diag], [-diag, diag], color="white", linewidth=1.3, alpha=0.55, zorder=7) ax.text(-2.1, 1.75, "BEAM SPLITTER", color=c_bs, fontsize=12, fontweight="bold", ha="left", va="center", zorder=8) ax.plot([-1.15, -0.5], [1.6, 0.5], color=c_bs, linewidth=1.1, linestyle=":", alpha=0.8, zorder=6) # --------------------------------------------------------------------------- # Mirror A (top arm, horizontal reflective surface facing down) # --------------------------------------------------------------------------- ax.plot([-0.9, 0.9], [MIRROR_A_Y, MIRROR_A_Y], color=c_mirror, linewidth=7, solid_capstyle="round", zorder=6) for hx in np.linspace(-0.82, 0.82, 9): ax.plot([hx, hx - 0.18], [MIRROR_A_Y, MIRROR_A_Y + 0.28], color=c_mirror, linewidth=1.3, alpha=0.7, zorder=5) ax.text(0, MIRROR_A_Y + 0.62, "MIRROR A", color=c_text, fontsize=13, fontweight="bold", ha="center", va="bottom", zorder=5) # --------------------------------------------------------------------------- # Mirror B (right arm, vertical reflective surface facing left) # --------------------------------------------------------------------------- ax.plot([MIRROR_B_X, MIRROR_B_X], [-0.9, 0.9], color=c_mirror, linewidth=7, solid_capstyle="round", zorder=6) for hy in np.linspace(-0.82, 0.82, 9): ax.plot([MIRROR_B_X, MIRROR_B_X + 0.28], [hy, hy - 0.18], color=c_mirror, linewidth=1.3, alpha=0.7, zorder=5) ax.text(MIRROR_B_X + 0.6, 0, "MIRROR B", color=c_text, fontsize=13, fontweight="bold", ha="left", va="center", rotation=90, zorder=5) # --------------------------------------------------------------------------- # Screen (bottom arm) with a simple interference-fringe pattern # --------------------------------------------------------------------------- screen_w, screen_h = 1.7, 1.9 screen_box = FancyBboxPatch( (-screen_w / 2, SCREEN_Y - screen_h / 2), screen_w, screen_h, boxstyle="round,pad=0.03,rounding_size=0.06", facecolor="#05070f", edgecolor=c_edge, linewidth=1.8, zorder=4, ) ax.add_patch(screen_box) fringe = np.tile(0.5 + 0.5 * np.cos(np.linspace(0, 10 * np.pi, 300)), (40, 1)) ax.imshow( fringe, cmap="gray", aspect="auto", zorder=5, extent=(-screen_w / 2 + 0.12, screen_w / 2 - 0.12, SCREEN_Y - screen_h / 2 + 0.12, SCREEN_Y + screen_h / 2 - 0.12), ) ax.text(0, SCREEN_Y - screen_h / 2 - 0.3, "SCREEN", color=c_text, fontsize=13, fontweight="bold", ha="center", va="top", zorder=5) # --------------------------------------------------------------------------- # Light paths (straight arrows) # --------------------------------------------------------------------------- # 1) Laser -> beam splitter (incoming beam) arrow((LASER_X + 0.85, 0), (-GAP, 0), c_beam_out) # 2) Beam splitter -> Mirror B (transmitted, outgoing) / Mirror B -> BS (returning) arrow((GAP, 0.14), (MIRROR_B_X - 0.06, 0.14), c_beam_out) arrow((MIRROR_B_X - 0.06, -0.14), (GAP, -0.14), c_beam_return) # 3) Beam splitter -> Mirror A (reflected, outgoing) / Mirror A -> BS (returning) arrow((-0.14, GAP), (-0.14, MIRROR_A_Y - 0.06), c_beam_out) arrow((0.14, MIRROR_A_Y - 0.06), (0.14, GAP), c_beam_return) # 4) Beam splitter -> Screen (recombined / interfered beam) arrow((0, -GAP), (0, SCREEN_Y + screen_h / 2 + 0.05), c_beam_combined, lw=3.4, mutation=22) # --------------------------------------------------------------------------- # Title + legend # --------------------------------------------------------------------------- ax.text(0, 6.15, "Michelson Interferometer", color=c_text, fontsize=20, fontweight="bold", ha="center", va="center", zorder=9) legend_elements = [ Line2D([0], [0], color=c_beam_out, lw=2.8, label="Outgoing beam"), Line2D([0], [0], color=c_beam_return, lw=2.8, label="Returning beam"), Line2D([0], [0], color=c_beam_combined, lw=3.2, label="Recombined (interference) beam"), ] leg = ax.legend( handles=legend_elements, loc="lower left", bbox_to_anchor=(0.0, 0.0), frameon=True, facecolor=c_box, edgecolor=c_edge, fontsize=10, labelcolor=c_text, ) leg.set_zorder(9) fig.savefig(output_path, facecolor=fig.get_facecolor())