input: def plot_power_vs_spectra(logfile: str, calib_folder: str) -> None:
      """ Perform a series of calculations and generate plots based on input data.
      The script performs calibration, calculates various power values, and generates 
      plots showing absorbed power vs emitted power, absorbed power vs reflectivity, 
      and dissipated power vs wavelength. It also calculates thermal resistance and 
      displays it on the plot. The instructions for plotting are read from a separate 
      text file.
      >>> plot_power_vs_spectra('../24_LL_ev/20150211_sample21-1-d6/spot333um.csv', '../24_LL_ev/20150204_calib_333um_s21-1-d6')
      """
output:     import os
      import pandas as pd
      import numpy as np
      import matplotlib.pyplot as plt
  
      # Read the logfile and calibration data
      log_data = pd.read_csv(logfile)
      calib_files = [os.path.join(calib_folder, f) for f in os.listdir(calib_folder) if f.endswith('.csv')]
      calib_data = pd.concat([pd.read_csv(f) for f in calib_files])
  
      # Perform calibration
      log_data['calibrated_power'] = log_data['power'] * calib_data['calibration_factor'].mean()
  
      # Calculate absorbed power
      log_data['absorbed_power'] = log_data['calibrated_power'] - log_data['emitted_power']
  
      # Calculate reflectivity
      log_data['reflectivity'] = log_data['emitted_power'] / log_data['calibrated_power']
  
      # Calculate dissipated power
      log_data['dissipated_power'] = log_data['absorbed_power'] * (1 - log_data['reflectivity'])
  
      # Calculate thermal resistance
      thermal_resistance = log_data['dissipated_power'].mean() / log_data['absorbed_power'].mean()
  
      # Plot absorbed power vs emitted power
      plt.figure(figsize=(10, 6))
      plt.scatter(log_data['emitted_power'], log_data['absorbed_power'], color='blue')
      plt.xlabel('Emitted Power')
      plt.ylabel('Absorbed Power')
      plt.title('Absorbed Power vs Emitted Power')
      plt.grid(True)
      plt.show()
  
      # Plot absorbed power vs reflectivity
      plt.figure(figsize=(10, 6))
      plt.scatter(log_data['reflectivity'], log_data['absorbed_power'], color='green')
      plt.xlabel('Reflectivity')
      plt.ylabel('Absorbed Power')
      plt.title('Absorbed Power vs Reflectivity')
      plt.grid(True)
      plt.show()
  
      # Plot dissipated power vs wavelength
      plt.figure(figsize=(10, 6))
      plt.scatter(log_data['wavelength'], log_data['dissipated_power'], color='red')
      plt.xlabel('Wavelength')
      plt.ylabel('Dissipated Power')
      plt.title('Dissipated Power vs Wavelength')
      plt.grid(True)
      plt.show()
  
      # Display thermal resistance on the plot
      plt.text(0.5, 0.5, f'Thermal Resistance: {thermal_resistance:.2f}', transform=plt.gca().transAxes, fontsize=12, ha='center')
      plt.show()