An optical system for distance measuring, the optical system comprising: a transmitter comprising: a laser pulse generator adapted to generate a series of laser pulses such that the laser pulses are delayed with respect to each other and such that at least some laser pulses have a wavelength different from the wavelengths of other laser pulses of the series of laser pulses; wherein the transmitter is adapted to transmit the laser pulses towards a target or object; and a receiver adapted to receive a series of laser pulses having been generated by reflection and/or scattering of the laser pulses transmitted by the transmitter from the target or object, respectively; characterized in that the receiver comprises: a first optical delay module adapted to delay laser pulses based on the wavelength of the respective laser pulses such that the magnitudes of delays of laser pulses having different wavelengths are different; wherein the first optical delay module is arranged such that the magnitudes of delays corresponding to different wavelengths are such that at least some of the laser pulses that are output from the first optical delay module overlap each other in time. a transmitter comprising: a laser pulse generator adapted to generate a series of laser pulses such that the laser pulses are delayed with respect to each other and such that at least some laser pulses have a wavelength different from the wavelengths of other laser pulses of the series of laser pulses; wherein the transmitter is adapted to transmit the laser pulses towards a target or object; and a receiver adapted to receive a series of laser pulses having been generated by reflection and/or scattering of the laser pulses transmitted by the transmitter from the target or object, respectively; a laser pulse generator adapted to generate a series of laser pulses such that the laser pulses are delayed with respect to each other and such that at least some laser pulses have a wavelength different from the wavelengths of other laser pulses of the series of laser pulses; wherein the transmitter is adapted to transmit the laser pulses towards a target or object; and a receiver adapted to receive a series of laser pulses having been generated by reflection and/or scattering of the laser pulses transmitted by the transmitter from the target or object, respectively; characterized in that the receiver comprises: a first optical delay module adapted to delay laser pulses based on the wavelength of the respective laser pulses such that the magnitudes of delays of laser pulses having different wavelengths are different; wherein the first optical delay module is arranged such that the magnitudes of delays corresponding to different wavelengths are such that at least some of the laser pulses that are output from the first optical delay module overlap each other in time. a first optical delay module adapted to delay laser pulses based on the wavelength of the respective laser pulses such that the magnitudes of delays of laser pulses having different wavelengths are different; wherein the first optical delay module is arranged such that the magnitudes of delays corresponding to different wavelengths are such that at least some of the laser pulses that are output from the first optical delay module overlap each other in time.