1 files changed, 136 insertions, 0 deletions
diff --git a/src/devices/detector.cpp b/src/devices/detector.cpp
new file mode 100644
index 0000000..b93a5de
--- /dev/null
+++ b/src/devices/detector.cpp
@@ -0,0 +1,136 @@
+#include "specs.h"
+#include <detector.h>
+#include <cstdlib> // system()
+#include <random>
+#include <complex>
+
+using namespace std;
+
+void Detector::on_port_in_changed()
+{
+    // always initialize memory
+    m_memory_in[0] = 0;
+
+    // rng seed
+    init();
+
+    while (true) {
+        // Wait for a new input signal
+        wait();
+
+        const auto &p_in_read = p_in->read();
+
+        auto cur_wavelength_id = p_in_read.m_wavelength_id;
+        // Updating the field memory
+        m_memory_in[cur_wavelength_id] = p_in_read.m_field;
+        m_event_manual_trigger.notify();
+    }
+}
+
+void Detector::on_time_tick()
+{
+    sc_time sampling_time = sc_time(m_sampling_time, SC_SEC);
+    if (sampling_time.value() == 0)
+        sampling_time = sc_time::from_value(1);
+
+    OpticalSignal::field_type total_field;
+    OpticalSignal::field_type::value_type total_power;
+    double photocurrent;
+
+    // Wait for enable signal
+    if (! enable.read().to_bool())
+    {
+        // cout << name() << " waiting for enable" << endl;
+        wait(enable.posedge_event());
+        cout << name() << " was enabled" << endl;
+    }
+
+    while(true)
+    {
+        if (sc_pending_activity()) {
+            wait(sampling_time, m_event_manual_trigger);
+            //wait(m_event_manual_trigger); // if only time-averaged signal is of interest
+        } else {
+            /* wait for reset */
+            //TODO (see CWSource code)
+            wait(); // effectively wait until the end of the simulation
+        }
+
+        /* Get current time tk*/
+        double tk = sc_time_stamp().to_seconds();
+
+        /* Calculate current output value based on present fields */
+        /* Calculate sum of fields at current time*/
+        total_field = 0;
+        total_power = 0;
+        for (auto field : m_memory_in)
+        {
+            double wl = specsGlobalConfig.wavelengths_vector[field.first];
+            double freq = 299792458 / wl;
+            total_field += field.second * exp(complex<double>(0, 2 * M_PI * freq * tk));
+            total_power += norm(field.second);
+        }
+
+        if (norm(total_field) == 0)
+            total_field = 1e-20*m_rngDist(m_rngGen);
+
+        photocurrent = norm(total_field) * m_responsivity_A_W;
+        m_cur_readout = photocurrent + (!m_noiseBypass)*noise_gen(photocurrent) + m_darkCurrent_A;
+        m_cur_readout_no_interf = total_power * m_responsivity_A_W + (!m_noiseBypass)*noise_gen(photocurrent) + m_darkCurrent_A;
+
+
+        //m_cur_readout = total_field.real();
+        // Write to output port
+        //p_readout->write(m_cur_readout);
+    }
+}
+
+/*
+Generates a current noise to be applied to the noiseless_readout,
+calculated from the responsivity.
+
+Considers: TIA input referred, shot, and thermal
+*/
+double Detector::noise_gen(const double &noiseless_readout)
+{
+    // elementary charge
+    const double q = 1.60217e-19;
+
+    // Boltzmann constant
+    const double K = 1.38064e-23;
+
+    double inoise_tia_2 = m_opFreq_Hz*pow(m_iTIA,2);
+    double inoise_shot_2 = m_opFreq_Hz*2*q*(noiseless_readout+m_darkCurrent_A);
+    double inoise_therm_2 = m_opFreq_Hz*4*K*m_temp_K/m_equivR_Ohm;
+
+    // the RMS value is also the variance of the random variable
+    double inoise_rms = inoise_tia_2 + inoise_shot_2 + inoise_therm_2;
+
+    // mean = noiseless, std = sqrt(variance)
+    // the second element of the product is the gaussian(0,1)
+    return sqrt(inoise_rms) * m_rngDist(m_rngGen);
+}
+
+/*
+To be implemented in the future, user can specify the wavelength response
+of the photodiode
+*/
+double Detector::wavelength_dependent_responsivity(const double &wavelength)
+{
+    (void)wavelength;
+    if(true)
+    {
+        return m_responsivity_A_W;
+    }
+    else
+    {
+        // custom responsivity curve
+        return 0; // should return the new responsivity
+    }
+}
+
+void Detector::init()
+{
+    std::random_device rd;  // Will be used to obtain a seed for the random number engine
+    m_rngGen.seed(rd());
+}