diff --git a/src/laser_diode/laser_diode.rs b/src/laser_diode/laser_diode.rs
index 95d30e8..3a4c047 100644
--- a/src/laser_diode/laser_diode.rs
+++ b/src/laser_diode/laser_diode.rs
@@ -16,8 +16,6 @@ use uom::{si::{ISQ, SI, Quantity}, typenum::*};
 pub type TransimpedanceUnit = Quantity<ISQ<P2, P1, N3, N2, Z0, Z0, Z0>, SI<f64>, f64>;
 // Ampere / Volt
 type TransconductanceUnit = Quantity<ISQ<N2, N1, P3, P2, Z0, Z0, Z0>, SI<f64>, f64>;
-// Watt / Ampere
-pub type IToPowerUnit = Quantity<ISQ<P2, P1, N3, N1, Z0, Z0, Z0>, SI<f64>, f64>; 
 
 impl Settings{
     pub const DAC_OUT_V_MAX: ElectricPotential = ElectricPotential {
@@ -131,6 +129,10 @@ impl LdDrive{
         self.settings.pd_responsitivity.responsitivity = responsitivity;
     }
 
+    pub fn set_pd_dark_current(&mut self, i_dark: ElectricCurrent){
+        self.settings.pd_responsitivity.i_dark = i_dark;
+    }
+
     pub fn set_ld_power_limit(&mut self, pwr_limit: Power){
         LdPwrExcProtector::set_trigger_threshold_v(self.settings.pd_responsitivity
             .get_ld_i_from_ld_pwr(pwr_limit) / Settings::PD_MON_TRANSCONDUCTANCE